Star Trek Online. I don't really know why anymore. The space combat is fun, I guess, but the ground combat is absolutely terrible. Yesterday I was about to ragequit (something I never do) because I was fighting Borg drones with walls of HP and every 2 seconds I had to stop shooting for 5 seconds to remodulate my weapons because their shields had adapted. Good Lord, that was annoying.
The quests are, in true Star Trek style, hit and miss by a mile. Some are fun and entertaining (the Q one was, as one would expect, a lot of fun (even with the aforementioned Borg annoyance. Hang on, I didn't need to remodulate my weapons during that mission. Weird.)), but most are just the same cycle of stages: go to system, fight ships, beam to planet/ship, fight footsoldiers, beam back to ship, fight ships, warp out and report.
Maybe I should try my hand at a little PVP, but before I do that I should get another class ship. But in true MMO spirit, that'll be weeks of saving dilithium or pay $20 or the local equivalent. $20 for a ship with marginally better stats for combat that really isn't that inspired... Yeah, I really don't know why I'm playing this anymore. ^^;