Chrono Trigger 150+ hours (I've played and beaten all 3 release versions several times over. I could beat the SNES version in under 9 hours.)
Dragon Quest IX 205 hours. (recent hours as I'm still playing)
Borderlands: 96 hours (recent hours still playing)
Final Fantasy IV (98), VI (84), VIII (75): 60+ hours a piece (I was way off on these.)
Wild Arms: 96 hours (way off here too)
Final Fantasy Tactics: 178 hours
Mass Effect: 132 hours
Mass Effect 2: 136 Hours
Xenogears (105), Star Ocean the Second Story(170), Suikoden 1 (104), Suikoden 2 (127): 65+ Hours a piece (I spent way to much time on these)
Everquest: 42+ Days
= 1008+ hours (this may be more, can't log into my account to check)
World of Warcraft: 26+ Days
= 624 Hours
Hard core MMO's win for time spent.
I'm missing other games, but they'll come back to me.