Pocket billiards!
But seriously it has to be European Football. I think one of the main reasons that a lot of Americans do not like it might be because the idea of going from losing a game to winning a game with literally the last throw or kick of the game is something that you guys love, and as such the scoring system of football probably slows the pace down in the eyes of an American sports fan IMO. There are no 0-0 draws in American sports.