Basketball and Baseball. Couldn't care less about either. Baseball is less exciting then golf on TV.
That said:
I'll watch the CWS on TV. I'll watch March Madness. I'll probably catch an NBA finals game or two.
I'll watch (women's) tennis if one of them is hot, once in awhile I'll check to see if Roddick is doing well (he's not, but he is a husker fan with a gorgeous wife so he's doing something right)...
I'll watch golf if its one of the big tournaments or I feel like having a lazy Sunday nap.
I'll flip between soccer once in awhile because the announcers crack me up, "name, other name, *extreme excitement* name... *back to monotone as the other side gets the ball* name" and repeat for an hour and a half.
The other thing soccer and tennis have going for them is they are on early since its mostly European which beats infomercials and crappy 10-20 year old movies. It was fairly interesting traveling through Europe during the French Open, tons of people crowded around airport bar TVs watching tennis or in local bars watching tennis, just way different.
I can't believe someone said hockey, it's right behind football for me if its a good game with a couple star players. It is full of fast paced action with tons of hitting.