A few off of the top of my head:
Playing golf...
...Just not for me
Watching other people play golf...
...Even worse than playing it
Getting all hyped up over a college sports team for a school you didn't attend and have no association with...I just don't get it?
Truck pulls... Your truck pulled the big heavy thing further than the other guy's truck, whoopee.
Any fantasy sport... The only "fantasy" sport I'm interested in is that all women's lingerie league.
Competitive fishing... I love fishing. My friends call me the Fish Whisperer. I could post pages upon pages of impressive fish pictures... But man, I hate bass tournaments. The whole point of going is to relax and maybe bring home some dinner while you're at it. Fishing in a tournament achieves neither. Plus I think it creates unnecessary stress and pressure on the fishery. The tournament guys in my area are real jackwagons too. They come flying in, crowd you, throw 10 casts, then go flying back out somewhere else. My dad calls them "The Bassholes"