1. Packers: They've still got some defensive concerns, but their Aaron Rodgers-led offense is the closest thing I've ever seen to unstoppable.
2. 49ers: Alex Smith isn't a great quarterback, but when you've got the league's best defense and a competent ground game, he doesn't need to be.
3. Patriots: They managed to make it to the Super Bowl last year with the league's 31st-ranked defense. With the pieces they added in the draft, their defense should be much better. And even if it's not, they've still got Tom Brady.