In the US its American Football(not soccer) and baseball then basketball followed by soccer. I would bet that more people actually play American football than baseball.
Even during the summer my friends and I would go to a field and play tackle football and have a blast or if not in the mood to play tackle then touch football or even a frisee game like Ultimate but we didn't play softball, baseball or soccer as much as American football.
To watch and actually play would be too different things. I would bet that more people watch baseball than actually play it and that there are more folks actually playing some form of American football, basketabll and even I dare say it, soccer in the US then baseball but the answer is usually we give more money to professional American football, baseball, then basketball followed by hockey and professional soccer.