Favorite sport to watch is easily American Football. It's really the only sport I do watch on a regular basis. NFL and NCAA Football all the way. I follow NBA and MLB, but don't really like them all too much. Same with golf and NHL.
Favorite sports to play? Ultimate Frisbee, Frisbee Tennis, Football. Hate playing baseball (and all incarnations, eg. kick ball, softball) and I suck at basketball way too much to play it.