Oh god.
WoW,
The Phoenix Wright series,
Meteos,
Elite Beat Agents,
Super Mario RPG: Legend of the Seven Stars (I think that's an all time favorite.)
The OLD Super Mario Brothers (Specifically One and Three)
Dead or Alive 4,
SSX Tricky and 3, (Only sports-ish game I've ever liked, I like Blur but it's not as great as the first three.)
Guitar Hero II,
Warioware Series (I looooove the Wii one,)
The Legend of Zelda (Specifically Link to the Past, OoT, and TP.)
Oh, right, completely forgot to put Tetris! Probably one of the most addictive things ever.
And those are my all-time favorites.