Let's review the basics here, since Bill C wants to get all statistical on your ass about "oh, who's the best program ever by decade." Statistics don't lie -- they lie repeatedly, and in robust data sets of dishonesty piled on dishonesty. They do not account for belly shirts and neck rolls, nor for leather helmets and pantaloon-style football pants. They do not account for the glories that lie outside victory, and do not measure the qualifiable greatnesses of a team.
1900s: Sewanee. You've probably never heard of them, and that instantly makes them cooler than any of the other possible choices. Also mostly dead, or in D-III, whichever you prefer to think of them as. Nothing's cooler than "they are dead, or in D-III." (See: Hal Mumme.)
1910s: Minnesota. Okay, Bill C's right on this because a.) Minnesota really deserves something in college football given the rest of their history, and b.) these people played football in an age where dealing with the cold involved applying wool and alcohol to the body until you started feeling 20% of your extremities. The Lockjaw Era Champions isn't the greatest prize in football, but it will have to do for you, Gophers.
1920s: USC. Okay, Bill's right here, too, if only because the 1920s are synonymous with real estate fraud, bathtub gin, and wearing varsity sweaters as a subversive act. Also, the 1920s are a decade of the private school rich drinking and burning money on the backs of the poor, which is again a very, very USC thing to do.
1930s: Pittsburgh. Ranked third in Bill C's rankings, which is incorrect because Pittsburgh is obviously the blue-collar, lunchpail match for the hardscrabble 1930s. Pitt is currently rusty and neglected, like many things built during the Roosevelt Administration, and is somehow still relatively functional, at least until it collapses and kills someone unexpectedly. (The someone will be Penn State.)
1940s: Michigan is Bill's pick, and that's correct because World War Two history is one of a Michigan Man's four passions along with woodworking, VERY THOUGHTFUL THOUGHTS ON POLITICS, and quiet drinking at dusk.
1950s: Ohio State is without a doubt the most 50s team, if only for the buzzcuts and fondness for Eisenhower and a belief that pushups and dairy products make up easily 90% of an individual's fitness program.
1970s: Oklahoma. We object to Alabama being chosen as the 1970s' team because they did not have this coach, these men, or these outfits.
Also the 1970s Sooners relied on someone else's ideas and corruption to succeed, and if that's not a history of the Nixon and post-Nixon eras, nothing is.
1980s: Miami. The data says Nebraska, but the data never fired a gun out of the window of the athletic dorms while cranking 2 Live Crew. The Miami Hurricanes are the most 1980s team because they encompass all three phases of the decade: the yacht rock hangover of the Schnellenberger era (BEV WORE A MINK AT THE VICTORY PARADE), the middle part where a ruthless guy with slick hair got large results before a huge crash, and the last part where no one was really in charge at all.
1990s: Tennessee. Terrible music? Unfortunate fashion choices? A bunch of vacations to Florida that seemed like the best at the time but now you look back and wonder why you didn't go to Europe or South America or Asia at least once? The Volunteers are a match on all three fronts. Think back: can you be sure Mopey Ethan Hawke wasn't a backup quarterback for one of these teams. You cannot.
2000s: West Virginia. The only choice, given that Dave Wannstedt also caused the 2008 recession. How a bank allowed him to take out a 30 year ARM using only his mustache as collateral, we'll never know.