In the 2000s, the champs among champs
NFL
Patriots 2007
New England set a record for points (589) and was the first undefeated regular-season team of the 16-game era. Forget the Super Bowl loss to the Giants: The 18--1 Pats still won more games than the 1972 Dolphins (17--0).
Baseball
Yankees 2009
Dominant regular season? Check. Postseason? Check. Nailing both isn't as easy as you think: The '09 Yanks were the only team of the decade to win 100 games and the World Series.
College Football
Miami 2001
The Hurricanes went 12--0, won the national championship and outscored opponents 512--117. They also flooded the NFL with talent: This team produced 16 first-round picks and 10 future Pro Bowl players.