Well, I've only played 4 games for more than 150 hours. Pokemon Gold/Silver (and Red/Blue), Melee and World of Warcraft.
As Pokemon has lost some of its glory to me, and I never want to go back to WoW, I choose either the sequel of the last one, Super Smash Brothers Brawl.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS