It could quite easily be argued that the goalkeeper is the most important player on the pitch.

There will always be some games when they're not called into action much, but they probably carry more responsibility than anyone else.

Some goalkeepers are blessed with bags of ability and a great presence around the penalty area to do their job, while others have to work at it.

Regardless of the nature vs. nurture argument, here are 20 of the most reliable goalkeepers in the world that most teams would feel safe guarding the back of their net.

So, in no particular order, here they are...

Iker Casillas

Age: 29

Club: Real Madrid

Nationality: Spanish

Reason: Quite probably the best goalkeeper in the World right now, Iker Casillas has won practically every major trophy going.

He was the starting goalkeeper for Spain during the triumphant Euro 2008 campaign and again, two years later, during the 2010 World Cup-winning campaign.

Casillas has also won La Liga with Real Madrid numerous times, as well as the UEFA Champions League twice.

He is the most capped goalkeeper of all time in the UEFA Champions League, was in the 2010 World Cup All-Star team and has been the No. 1 goalkeeper in FIFA's World XI for the last three years running.

Goalkeepers don't come much better than this.

Igor Akinfeev

Age: 24

Club: CSKA Moscow

Nationality: Russian

Reason: One of the most underrated goalkeepers in the world, Akinfeev has slowly been earning the attention he deserves over recent years.

He has made 47 appearances for the Russian national team and has been rated as their No. 1 choice for years.

Akinfeev won the UEFA Cup with CSKA Moscow in 2005, just a few years before it was rebranded as the Europa League.

He was a key player in Russia's run to third place in the Euro 2008 Championship and was one of the best goalkeepers at the tournament.

Akinfeev's domestic trophy case speaks for itself as he has won the Russian Premier League three times, the Russian Super Cup four times and the Russian Cup four times.

Edwin Van Der Sar

Age: 40

Club: Manchester United

Nationality: Dutch

Reason: Edwin van der Sar is arguably one of the top goalkeepers in the world right now and has been for a very long time.

His career has been filled with many different trophies which only begin to reflect the talent this goalkeeper has.

He is a two-time winner of the Champions League and a three-time English Premier League winner. He also holds the worldwide record for the longest clean sheet in any domestic league, having not conceded for 1,311 minutes.

Van der Sar is one of the greatest goalkeepers of his generation, if not the greatest, and already has his name written into the record books.

The fact that he's still going at 40 just proves how talented he is.

Pepe Reina

Age: 28

Club: Liverpool

Nationality: Spanish

Reason: One of the top goalkeepers in the world, who hasn't always been given the credit he deserves.

Reina is generally regarded as the second-choice Spanish goalkeeper behind Iker Casillas, but ahead of Victor Valdes.

Reina has never won the Champions League but did reach the final with Liverpool in 2007, as well as finishing as Premier League runners up in 2009.

Reina won the Barclays Premier League Golden Glove award for three years running between 2006 and 2008, and was Liverpool's player of the season in 2009-2010.

Victor Valdes

Age: 29

Club: Barcelona

Nationality: Spanish

Reason: If it hadn't been for Reina and Casillas, Valdes would easily have been Spain's No. 1 goalkeeper and would in fact comfortably jump straight into the shirt for most countries on the planet.

Valdes is the goalkeeper for what is arguably one of the best clubs the world has ever seen. With them, he is a two-time Champions League winner and has won many other trophies, too.

Valdes was included in Spain's 2010 World Cup-winning squad, despite not make an appearance due to the unbelievable form of Iker Casillas.

He has so far made just three appearances for the Spanish national team, which sadly does not reflect on his great ability.

Having been to numerous cup finals with Barcelona, Valdes is definitely a safe pair of hands protecting the goal.

David De Gea

Age: 20

Club: Atletico Madrid

Nationality: Spanish

Reason: If you hadn't realised already, Spain are truly blessed when it comes to top-class goalkeepers.

David De Gea has only come onto the scene recently, but at 20 years old, he's already seen as the future of the Spanish national team.

Manchester United have already marked him as a replacement ahead of the impending departure of Edwin van der Sar.

De Gea has already made over 45 appearances for Atletico Madrid at the highest level, as well as being a key player in the club's victory in the UEFA Europa League and UEFA Super Cup in 2010.

Thanks to De Gea, Atletico Madrid were also runners up in the Copa Del Rey in 2010.

Manuel Neuer

Age: 24

Club: Schalke 04

Nationality: German

Reason: The starting German goalkeeper in the World Cup, Manuel Neuer is also currently in the Champions League quarterfinals with Schalke 04, following a number of great performances throughout the tournament.

Having made 16 international appearances for Germany already, he looks set to be the nation's No. 1 goalkeeping choice for a long time to come, and therefore has bags of experience in multiple competitions.

Manuel Neuer has already earned a World Cup bronze medal with Germany, as well as the German League Cup title with Schalke.

There can be no doubt he'll have far more opportunities in the future to increase his trophy count as well.

Hugo Lloris

Age: 24

Club: Olympique Lyonnais

Nationality: French

Reason: Despite suffering a poor World Cup in 2010, Hugo Lloris is still one of the top young European goalkeepers around nowadays.

In fact, his worth to the national team was shown when he captained the country for the first time against England in November 2010.

Hugo Lloris has not won any major trophies with either France or Lyon as of yet, but will still have many chances to win competitions in the future.

Individually, however, he has won the French Ligue 1 Goalkeeper of the Year for the past two seasons running, as well as being in the Ligue 1 Team of the Year for both seasons as well.

Lloris has had rumours circulating about him, having drawn interest from top European clubs including Arsenal—although, at the moment, he has said he is happy with Lyon.

Maarten Stekelenburg

Age: 28

Club: Ajax

Nationality: Dutch

Reason: Had it not been for Maarten Stekelenburg, Ajax would have suffered some very heavy defeats in the Champions League group stage this past year.

The Dutch goalkeeper has been in such good form that he was selected as the first choice goalkeeper to lead the Netherlands to the 2010 World Cup Final.

Stekelenburg is the replacement Dutch goalkeeper for the famous Edwin van der Sar and—although having achieved less—is still rated as having done a very admirable job following in his footsteps.

He has been mooted as a potential successor to the very same goalkeeper at Manchester United as well.

Stekelenburg has won the Eredivisie with Ajax once in his career, the KNVB Cup three times and the Johan Cruyff Shield twice.

Gianluigi Buffon

Age: 33

Club: Juventus

Nationality: Italian

Reason: Buffon should need no introduction to anyone who has been following football over recent years.

He is rated as one of the top goalkeepers of all time, has won the Serie A goalkeeper of the year a record eight times, as well as taking numerous other honours in his time.

Internationally, Buffon won the 2006 FIFA World Cup with Italy, which caused him to be included in multiple international Team of the Year awards.

He has won the Serie A twice with his club Juventus, as well as winning the Supercoppa Italiana three times.

Despite never having won the UEFA Champions League, Buffon is regarded as possibly the best goalkeeper of his generation.

Petr Cech

Age: 28

Club: Chelsea

Nationality: Czech

Reason: Petr Cech is another goalkeeper who should need no introduction to football fans around the globe.

The Chelsea goalkeeper held the record for most league games without conceding a goal, standing at 1,025 minutes, before Edwin van der Sar went on to beat the record last year.

In 2010, the IFFHS included him as one of the world's five best goalkeepers along with Iker Casillas, Julio Cesar, Manuel Neuer and Maarten Stekelenburg.

Although Cech has never won the Champions League or World Cup, he has still been very successful with Chelsea, taking them to one Champions League final, three Premier League titles and three FA Cup titles.

Petr Cech is no doubt one of the safest pairs of hands to have in goal in the world.

Julio Cesar

Age: 31

Club: Inter Milan

Nationality: Brazilian

Reason: Having won the Confederations Cup and the Copa America with Brazil, Julio Cesar is one of the best goalkeepers in the world today.

He has also won the Serie A five times with Inter Milan as well as the treble in 2010—including the UEFA Champions League.

Following their success in the Champions League, Julio Cesar also played a key role in Inter Milan's success during the 2010 FIFA World Club Cup.

After his success, particularly in 2010, he was awarded his second consecutive Serie A Goalkeeper of the Year award as well as the UEFA Club Goalkeeper of the Year award.

He was Brazil's starting goalkeeper in the 2010 World Cup, helping them reach the quarterfinals, but suffered a rare mistake which led to their exit from the competition.

Regardless, Cesar is still another one of the world's top keepers at the moment.

Sebastien Frey

Age: 30

Club: Fiorentina

Nationality: French

Reason: Although having never won any major trophies, Sebastien Frey has still been one of Europe's top performers in goal over the last decade.

Frey began his career with Cannes before moving to Serie A at just 19. Since then, he has had successful spells at Inter Milan, Parma and now Fiorentina.

He has a reputation as being quite an eccentric goalkeeper, often making saves more spectacular than they needed to be.

Frey was a part of the France squad who took part in Euro 2008, but because the nation has so many other strong goalkeepers, he has only ever managed to make two international appearances.

While his resume may not be as good as it deserves to be, Sebastien Frey is definitely a solid goalkeeper to have in any match.

Joe Hart

Age: 23

Club: Manchester City

Nationality: English

Reason: Like some of the other goalkeepers on this list, Joe Hart has never won any major trophies—but in his case, he has time on his side.

Rated as one of the best young goalkeepers in the world, Hart has received praise from some of the best keepers in history, including Gordon Banks, Gianluigi Buffon and Iker Casillas.

In the 2009/2010 season, Joe Hart won the best Premier League goalkeeper award following a string of great performances while on loan at Birmingham City.

He became England's No. 1 goalkeeper soon after the 2010 World Cup and has also managed to replace Shay Given as Manchester City's top goalkeeper.

Hart has so much time left in his career to win a major trophy and he has definitely given himself the best chances possible to do so.

Samir Handanovic

Age: 26

Club: Udinese

Nationality: Slovenian

Reason: Another one of the goalkeepers on this list who has not won either the UEFA Champions League or FIFA World Cup, but still deserves much credit.

Handanovic has made over 42 appearances for his nation, including playing a key role in the World Cup in 2010.

He has been a massively important part of the Udinese squad over recent years, helping them come close to winning domestic trophies on a number of occasions.

While he isn't one of the most recognised keepers in the world, Handanovic is another player who would always be a safe option in a cup final.

Craig Gordon

Age: 28

Club: Sunderland

Nationality: Scottish

Reason: Arguably an inclusion based on opinion, Craig Gordon is one of the best goalkeepers Scotland has produced in recent years. In fact, in 2010, he was one of the nominees for "Scotland's Greatest Ever Football Team" run by STV.

In 2007, after a 1-1 draw between Italy and Scotland, Gianluigi Buffon claimed that Craig Gordon could be one of the best goalkeepers in the world after seeing him put in a phenomenal performance during the game.

He has also drawn praise from former player Allan Preston, who said he could be one of the best goalkeepers in Europe.

Gordon may not always put in his best performances but when he's on top form he can match most of the other top European goalkeepers.

Rene Adler

Age: 26

Club: Bayer Leverkusen

Nationality: German

Reason: Another very talented German goalkeeper, Adler was a part of the Germany team that reached the Euro 2008 final.

He looked set to be part of the Germany squad for the 2010 World Cup as well, but he suffered a major rib injury just before the tournament which prevented him from going to South Africa.

In 2008, Rene Adler won the award for best Bundesliga goalkeeper thanks to his outstanding performances throughout the season.

Adler has spent all of his senior career at Bayer Leverkusen and has helped them on numerous occasions come close to winning domestic silverware. Although his record may not show it, Adler is another goalkeeper very deserving of being included in the Top 20 in the world.

Jussi Jaaskelainen

Age: 35

Club: Bolton Wanderers

Nationality: Finnish

Reason: Having been Bolton's goalkeeper for the past 14 years, Jaaskelainen is not only a club legend, but also a Premier League legend.

He has made over 500 appearances for the Premier League outfit and over that time has proved as safe a pair of hands as you are likely to find anywhere else in the league.

Were it not for the occasional dodgy defence at Bolton, Jaaskelainen may have had even more recognition than he already has.

Jaaskelainen has not won any major silverware in his career although he did help Bolton reach the English League Cup Final in 2004.

The goalkeeper is one of the most widely respected players not only in the Premier League but also in Europe for his experience and commitment.

Mark Schwarzer

Age: 38

Club: Fulham

Nationality: Australian

Reason: Another one of the most experienced goalkeepers in both the Premier League and Europe, Mark Schwarzer has provided Fulham with a very safe pair of hands after replacing Edwin van der Sar.

Before then, Schwarzer played for Middlesborough, being one of the main reasons they had remained in the Premier League as long as they had.

Internationally, Schwarzer is Australia's all-time most capped player and arguably the best goalkeeper to have come out of the country.

He was the starting goalkeeper for the country in both the 2006 and 2010 World Cups.

He helped Middlesborough claim the Football League Cup in 2004 and reach the UEFA Cup Final in 2006, before playing a key role in Fulham's march to the 2010 Europa League Final.

Heurelho Gomes

Age: 30

Club: Tottenham Hotspur

Nationality: Brazilian

Reason: Gomes can be slightly inconsistent and erratic at times—but when he's on top of his game, he can be unbeatable.

Playing backup to Julio Cesar in the Brazil squad, Gomes has 11 international caps for his country.

Gomes holds the record in the Eredivisie for the highest percentage of clean sheets in league games, standing at an amazing 60 percent.

In 2009, he was rated as the official best goalkeeper in the Premier League, beating out competition from other players such as Petr Cech and Edwin van der Sar.

He has won the Eredivisie four times with PSV, as well as being a part of the Brazil squad that won the last two Confederations Cups.

Honourable Mentions

Diego Lopez, Villareal: Just missing out on the list, Lopez is a hugely capable goalkeeper as he has proved regularly in one of Europe's toughest leagues.

Christian Abbiati, AC Milan: Earlier in his career, Abbiati was one of the top goalkeepers in the World, if not the best. He has dropped since then, but is still hugely talented.

Ben Foster, Birmingham City: Not necessarily one of the top goalkeepers in Europe, but his experience in cup finals has been phenomenal. He has taken part in the last three Carling Cup finals and won all of them, playing a key role in two.

Roman Weidenfeller, Borussia Dortmund: Another one of the top German keepers who has been put just behind Manuel Neuer and Rene Adler in the German national team pecking order.

Vyacheslav Malafeev, Zenit Saint Petersburg: One of Russia's most reliable goalkeepers over recent years, he has spent all 11 years of his career at Zenit, making 16 international appearances as well.

Volkan Demirel, Fenerbache: The starting goalkeeper of the Turkey side that reached the semifinals of Euro 2008, Demirel has been one of the most consistent Turkish goalkeepers in history.