None, really. I log in on Guild Wars 2 every so often to play with friends, but that's about it.
I used to play Warhammer Online while it was still a thing, might look for a private server or something for that one, cause it was kinda cool I guess.
I played SWTOR, I would have prefered it as a single player game though, cause the personal story is excellent. I heard that the next expansion will be a bit more single player oriented so it's also a game I might pick up again.
Besides that I've played Aion, which wasn't very good, WoW, which I have zero interest in picking up again and a little bit of Star Trek Online, which was cool, creating your own alien race was a cool feature, but I didn't get super captivated by it.
Also as far as MMOs go, I am really excited for Warhamer 40000: Eternal Crusade, so that's a game I will play when it comes out.