RPG majority of the time, typically it takes quite a while for me to find people i actually wouldn't mind playing with regularly, other then that sometimes it's not bad to group up with random people.
also, i only play like 2 games (being LoL and Wizardry atm) because they're interesting and different from the other 99% of MMOs. i tried HoN but i didn't like it, and I'm to cheap to pay for DOTA to try it. for Wizardry it's a refreshing (ironically) new experience of never ending tension. game is so unforgiving sometimes and the risk of someone looting your body or the very very slight chance of permadeath makes it that much worse when you die make it that much worse.
well, i suppose from that i guess you can say i like games that keep me engaged? i can't stand mindless grinding or there being 0 risk in the games i play. they need to be cruel, unforgiving, and/or a new experience every time i play.