Here are a few that might work for you. I think all of them are currently on Netflix:
Battlestar Galactica (can be dry, but once you get past the first 10 episodes, it gets better. Plus there's a LOT of hours available to keep you on the bike.)
Sherlock (The new BBC series. Not too many episodes yet, but tons of fun.)
Dr. Who (Again, lots to watch and not too serious most of the time. Might be just the thing to watch during physical activity.)
How about a re-watch of X-Files or any of the Star Trek series? Some older stuff here, but possibly worth a dip into pre-2000 television.
As far as comedies, I'm a fan of Arrested Development and Archer, but I totally realize taste varies a lot from person to person.
I also like the videos available on the PBS website for a change of pace. Hard to beat a good NOVA, Nature, etc.
Stuff I haven't seen, but my friends like a lot:
True Blood (if you have access to HBO)
Eureka and Warehouse 13 -- These are (sort of) related TV shows from SciFi Channel. I've seen a handful of episodes of each and they can be kind of lame-o, but also fun and not too serious, so good for being on the bike. Also BF likes 'em. Who knew?