Well, currently, only mmo I'm playing is STO. But I'm tearing up some Skyrim and Fallout NV, especially Skyrim with mods. Took 20 companions out into the woods, erected a bunch of shelters, and basically live there now, lol. It's pretty awesome.
None, because of the time sink an MMO demands and limited time. I tried SWTOR but dumped that like a hot potato. I break up my play time with a few Steam games like Portal 2. Looking forward to The Secret World due in the next couple of months .
I have been playing a lot of STO for the past year, but my primary MMO world has been, and still is Dungeons & Dragons Online. With a huge expansion launching soon to DDO, I may not be here to not play the coming gated content.