It is essentially the same game with a few rule differences but the championship format is completely different and the players are all amateurs between the ages of 18 and 22 as a norm....college kids. To me, the college game is more exciting and controversial than the NFL so I like it better.
The sudden death in NFL is somewhat horseshit. My buddy and I were just talking after the vikes lost about how really it's all luck - the toss of a coin, more or less. They need to revise the system somehow.
From the list: I like playing soccer the best, but for entertainment purposes, I'd just go with NHL/hockey, although I love to watch the World Cup and I have to watch all the heavyweight fights because boxing rocks.