The best game I have ever played is Dungeon Siege I and its expansion, Dungeon Siege I Ledgends of Aranna.
Final Fantasy 12 is my favorite game
Good topic, Briar.
I have to say the best game for me was probably Tony Hawk's Pro Skater 4. I still play it on my PC from time to time, but it isn't as fun on PC due to controller headaches. Still, it is a very good skateboarding game, and Skate isn't available on PC, anyway. THPS4 gave me just enough challenge to keep things exciting, and it offered plenty of humor and a lot of multiplayer modes.
My favorite game was Fallout: New Vegas Still is until Diablo 3 comes out.
My favorite game would have been Dungeon Siege 3, but the way they made the game is just so unappealing to me, after enjoying Dungeon Siege 1 and ledgends of Aranna.