Want an easy way to generate debate? Ask 10 fans who they believe is the greatest team in college football history, and you're likely to receive several different answers.

This conversation demands a hefty qualifier.

When discussing every team in the 150-year history of the sport, disagreements are both expected and understandable. There is no inarguable way to compare the many, many thousands of teams in a game that has continually evolved over time.

For this ranking, we focused on undefeated teams that won a national title, Yes, one-loss teams can be excellent, and the process of determining a champion has never been perfect. But some of those candidates are listed in the honorable mentions.

Honorable Mentions

1945 Army Black Knights: Army defeated five ranked teams and produced five shutouts in this 9-0 campaign. Running backs Doc Blanchard and Glenn Davis finished first and second, respectively, in Heisman Trophy voting.

1947 Michigan Wolverines: Capped by a 49-0 beatdown of USC in the Rose Bowl, Michigan went 10-0 with six shutouts.

1947 Notre Dame Fighting Irish: They finished 9-0 and allowed only 52 points all season. Notre Dame quarterback Johnny Lujack won the Heisman that season.

1968 Ohio State Buckeyes: Ohio State toppled second-ranked USC 27-16 in the Rose Bowl to claim the championship. This is the same season in which head coach Woody Hayes opted to go for a two-point conversion after already hanging 50 on rival Michigan.

1974 Oklahoma Sooners: Although being on NCAA probation for recruiting violations kept Oklahoma from winning a title, history doesn't forget this dominant year. The Sooners led the country with 43.0 points per game and ended 11-0 with 10 victories of at least 14 points.

1987 Miami Hurricanes: Miami opened and closed 1987 with three straight wins over ranked opponents, including No. 4 Florida State and, in the Orange Bowl for the title, No. 1 Oklahoma. The 'Canes ceded just 10.4 points per game.

1994 Penn State Nittany Lions: Nebraska claimed the national title, but Penn State had a spectacular year. Quarterback Kerry Collins and running back Ki-Jana Carter led the Nittany Lions to a nation-best 47 points per game, and they defeated four Top 25 teams and finished with a 12-0 record.

2008 Florida Gators: The September loss to Ole Miss keeps Florida in the honorable mentions. It also served as the spark for quarterback Tim Tebow's speech and a ridiculous end to the year. The Gators trashed six Top 25 foes by a combined score of 256-86.

2013 Florida State Seminoles: At the time, Florida State set a single-season record with 723 total points. Quarterback Jameis Winston won the Heisman, and the 'Noles walloped four Top 25 opponents by at least 38 points before edging Auburn for the national title.

10. 1956 Oklahoma Sooners

Only four of Oklahoma's 10 opponents even scored a point against them.

The Sooners allowed just 51 points all season, second in the nation. On top of that, they also averaged 46.6 points per game—a ridiculous 16.0 points higher than the No. 2 offense.

Running backs Tommy McDonald and Clendon Thomas both surpassed 1,000 yards from scrimmage and combined for 33 touchdowns. Additionally, McDonald and offensive lineman Jerry Tubbs finished third and fourth, respectively, in Heisman voting.

The 10-0 campaign marked a third straight undefeated year for OU, which also won 47 consecutive games from 1953 to 1957.

9. 1979 Alabama Crimson Tide

In 1979, Alabama earned the last of six national championships under legendary head coach Bear Bryant.

While surrendering just 5.6 points per game, best in the nation, the Crimson Tide posted five shutouts en route to a 12-0 record. They defeated 10 of those 12 opponents by at least 10 points.

Alabama leaned heavily on its wishbone attack and attempted just 112 passes all season. Starting quarterback Steadman Shealy ran for 791 yards and 11 touchdowns, while running backs Steve Whitman and Major Ogilvie both topped 500 yards.

8. 2005 Texas Longhorns

If the 2006 Rose Bowl isn't the greatest game ever played, it's certainly no lower than the highest tier in history.

Vince Young's legendary fourth-down scramble gave Texas a dramatic win over USC—then considered a potential all-time team. Given that context, how could the unblemished Longhorns not then be catapulted into that discussion?

Texas allowed just 16.4 points per game, but Young and Co. demanded the headlines with a top-ranked 50.2 points scored per game.

Young, who finished second in Heisman voting behind USC's Reggie Bush, became the first NCAA player to throw for 3,000 yards and run for 1,000 in a single season. Running back Jamaal Charles, a future NFL star, topped 1,000 scrimmage yards, too.

7. 2018 Clemson Tigers

After a 5-0 start that featured two very narrow wins, the Trevor Lawrence-led Tigers became a juggernaut. They outscored their final 10 opponents 474-113, including a 74-19 edge in two College Football Playoff games against No. 3 Notre Dame and No. 1 Alabama. 

Lawrence, a true freshman, threw for 3,280 yards and 30 touchdowns with only four interceptions. Running back Travis Etienne piled up 1,658 yards and 24 scores, finishing seventh in Heisman voting.

Clemson led the country in several defensive categories, most notably allowing just 13.1 points per game.

6. 2019 LSU Tigers

While assembling the most prolific offensive year in Football Bowl Subdivision history, LSU defeated seven Top 10 teams.

Quarterback Joe Burrow smashed FBS records along the way, capping his improbable breakout season with 5,671 yards and 60 touchdowns through the air. Wide receivers Ja'Marr Chase and Justin Jefferson both hauled in 80-plus receptions for at least 1,500 yards and 18 touchdowns apiece.

Put simply, merely keeping up with LSU was an accomplishment.

The Tigers tallied a single-season record of 726 points, scoring no fewer than 36 points in 14 games of a 15-0 year.

5. 2004 USC Trojans

USC sidestepped a few landmines in Pac-10 play, toppling four league opponents by eight points or fewer.

Still, the Trojans never ranked lower than No. 1 in the country.

The wire-to-wire champions blasted second-ranked Oklahoma 55-19 to secure the national title. USC knocked off two other programs, Virginia Tech and Cal, that would finish in the Top 10 and boasted the Heisman Trophy winner in quarterback Matt Leinart.

Reggie Bush piled up 2,330 all-purpose yards and accounted for 16 combined touchdowns that year before his own (since-vacated) Heisman win. USC also had a consensus All-American in defensive tackle Shaun Cody.

4. 1995 Nebraska Cornhuskers

What we said about LSU? Yeah, that was effectively a repeat of 1995 Nebraska in a slightly less dominant way.

This 12-0 squad registered 35-plus points in every game, including six showings of 50 or more. In the Fiesta Bowl against second-ranked Florida, the Huskers cruised to a 62-24 victory. Opposite three other Top 10 teams, they won by a combined score of 134-49. No team lost to Nebraska by less than 14 points.

Option quarterback Tommie Frazier tossed 17 touchdowns while running for 604 yards and 14 scores. Running back Ahman Green paced the Cornhuskers with 1,086 yards on the ground and 16 total touchdowns.

3. 1972 USC Trojans

USC breezed through its 12-game slate in 1972, defeating 11 of its opponents by at least 17 points.

The final triumph was a dominant 42-17 win over No. 3 Ohio State in the Rose Bowl, giving the Trojans six total victories over ranked teams for the season.

No player finished in the top 10 of Heisman voting, but five Trojans garnered some level of All-American recognition. That group included running back Anthony Davis—who scampered for 1,191 yards and 17 scores—and tight end Charles Young.

2. 1971 Nebraska Cornhuskers

After claiming the 1970 national title, Nebraska only improved.

In 1971, the Cornhuskers ranked third and second, respectively, in scoring offense (39.0) and defense (8.0). They held 10 opponents to seven points or fewer, most notably No. 2 Alabama in the Orange Bowl. Nebraska won that matchup 38-6.

Jerry Tagge threw for 2,178 yards and 17 touchdowns, while Jeff Kinney ran for 1,136 and Johnny Rodgers—who would win the Heisman Trophy in 1972—caught 57 passes for 956 yards. Plus, defensive lineman Larry Jacobson won the Outland Trophy as the nation's best interior lineman.

1. 2001 Miami Hurricanes

Nearly everywhere you looked, the 2001 Miami Hurricanes had a future NFL star. That talent showed itself in a legendary way.

"I know this," Art Kehoe said. "I will put that 2001 team up against anybody. No one can argue how good, how dominant, that team was."

Kehoe should know too; he served as an assistant coach for all five championship-winning Miami teams.

The 'Canes allowed just 9.8 points per game and defeated five Top 15 opponents by a combined score of 236-72.

Quarterback Ken Dorsey won the Maxwell Award, running back Clinton Portis had 1,200 yards on the ground, and offensive tackle Bryant McKinnie earned the Outland Trophy. On the other side of the ball, defensive back Ed Reed grabbed nine interceptions and secured unanimous All-American honors, helping to round out the best team in college football history.