I know its not a 2004 game but the one i have spent the most playing is Final Fantasy X must be my favorite game so far ever. Its been a barron year for PC games if you ask me, mothing has really jumped out at me as WOW great game. I guess the most hours spent in front of my PC have been on MTW :VI, and Championship/Football manager games.

Am Currently spending Hours on my PS2 with X-men: Legends