Currently playing EVE Online on the MMO front, Dwarf Fortress (so help me), and several DS games (Final Fantasy 4, Tactics A2, New Super Mario Bros., Arkanoid).
Also recommend the Dawn of War series for the PC, as well as Team Fortress 2 (the entire Orange Box).
I don't have much on the 360 (fiance picked the games out for it so far), I can recommend Dynasty Warriors 5 (not 6) (XB360, PS2), possibly Dynasty Warriors: Gundam (XB360). I can also recommend looking for and picking up Warriors Orochi or Okami for the PS2 (was recently ported to the Wii).