I like watching the Olympics. I think I enjoy the water sports the best - white water kayaking, rowing, synchronized swimming and water polo.
I really like watching the white water kayaking. It's pretty easy to understand; you can tell who's doing well and who isn't. Mostly though, it just looks like awesome fun, and it's neat that they construct the whole course like that.
Water polo is interesting just for its brutality. Seems like the toughest sport, to me...a bunch of jacked up dudebros trying to almost-drown each other.
I may watch a bit of the basketball, for the strangeness of it (generally speaking, I like the international rules better than the NBA's).