D&D, RuneQuest and Labyrinth Lord
Call of Cthulhu has always been a favourite but I'm also enjoying running Savage Worlds of late.There are a whole bunch of games I'd like to play, but there never seems to be the time.
Mostly I just play AD&D, but I enjoy reading most RPGs. I have tried out a number of different systems, mostly when I was younger and had more time. Some of them I'd like to have played more and just never found the group that was interested enough, like Pendragon or Twilight: 2ooo or FASA's Star Trek RPG or West End's Star Wars RPG or even GURPS. Everyone defaults to D&D/AD&D though, it's simple and everyone already knows how to play. I suppose that's not really true now that 3rd and 4th edition have come around, but it used to be, and it's still easy enough to teach new people interested in the hobby.
Play and enjoy playing D&D4e - as you know, since I nearly killed you all on Sunday.Board games - Advanced Civ, Arkham Horror, Porto Rico, several more whose names I cannot remember, but I enjoyed.Card type games - Gloom was very good.RPGs I want to play or run with a burning passion: Houses of the BloodedChronica FeudalisAl-Shabhiri RoachBackswords and BucklersTesting your OA stuffMythic RussiaThe list is fairly endless.
Savage Worlds as well please.Never played Call of Cthulu, but see Arkham Horror above