I've become massively into Starcraft II, which is odd, because I was never particularly into the original version of the game. I couldn't understand the appeal originally and preferred WoW, but I'm kinda hooked now.
I recently started to play FrontierVille in Facebook look interesting game but it is taking my time of work
If we're talking MMORPG, then Runescape or WoW, but if we're talking games that are played online, then definitely BF2.