I would sign up to any MMORPG just to hang out with other ABDLs (assuming it's free and not specific to a console). I have characters on all of the above bar Runescape (I didn't even realise that was still going!)
I just decided to download TERA myself last night. I played it way back when it first went free to play but I had a terrible computer back then that could barely run it.
As for other FTP MMORPG's. I'm a pretty big Wildstar fan, it's got a great sense of humor and the gameplay is really great. All enemies telegraph their attacks and can be interrupted. Raiding in it is really rewarding and fun. PvP is awesome as well but not very active.
Mabinogi is probably my favorite MMORPG as of right now, I don't play very much anymore though. After G3 I felt like it went a bit down hill. Making things way too easy and such. I do pop on now and again just to see what is new. Or if there is some sort of event going on and I actually happen to know about it, then I will pop on then too XD.