I used to be a huge NFL nut. Watched as many games as I could, could name most of the starters on every team, knew all the weaknesses and strengths....it was crazy. Over about a 7 or 8 year period, I slowly lost interest in almost all NFL and was completely taken over by NCAA. At this point, if it doesn't directly involve the Bills, I hardly take notice. Meanwhile, I watch every college game I can, no matter the team, conference, or subdivision. Yes, the BCS adds a sour note, but anyone who doesn't watch for that is missing out, and not really a college fan.
Those kids hit the field every game with everything on the line. They pour their hearts into the game, playing for the pride of the their schools, their states, hopes of a future in the NFL, or even just their popularity on campus (which I'm sure is a big enough prize for a 19 year old kid being treated like a god). Doesn't matter who's playing. Could be perennial top 10 team vs a long time bottom dweller, there's always the chance of an upset, and they always give it everything they have.
There may be rules that could be better, and a playoffs are must that will become a part of the game sooner or later. But for pure football, I don't think the NFL comes close.