As sports go, I honestly think that modern US football is one of the worst out there. First, it's simply not a good game. Fundamentally, the rules are designed around selling commercials, and keeping high cash generators in power, not around sport. I accept that all professional sports do this to a certain extent, but the level that the NFL does it seems to be the worst that I am aware of. Combining that with the issues of flagrant cheating with no consequences, protecting players who are dangerous criminals, and literally causing brain damage to the players, and it's simply not a league I can support.