Hmm... I should point out that I was a huge game quitter for the first 15 years of my life, so this is going to be a pretty pathetic list.

Richard Scarry's Busy Town ()
Crash Bandicoot 3
Zelda: A Link to the Past
Zelda: Ocarina of Time
Zelda: Phantom Hourglass
Pokemon Red
Pokemon Silver
Guitar Hero 2
Guitar Hero 3
Harry Potter and the Sorcerer's Stone (PSone)
Professor Layton and the Curious Village
Cooking Mama 1
Cooking Mama 2
Trauma Center (2, I think)
WarioWare Touched
Warioware (on Wii)
DDR max 2
Picross
Chrono Trigger
Bully
Kingdom Hearts
Kindom Hearts Chain of Memories
Kingdom Hearts Re: Chain of Memories
Kingdom Hearts 2
Kingdom Hearts 358/2 days
Final Fantasy I
Final Fantasy II
Final Fantasy III
Final Fantasy IV
Final Fantasy V
Final Fantasy VI
Final Fantasy VII
Final Fantasy VII Dirge of Cerberus
Final Fantasy VII Crisis Core
Final Fantasy X
Final Fantasy X-2
Final Fantasy XII
Shadow of the Colossus
Where in Time is Carmen SanDiego?

Yeah, wow. That might just be all of them. Seriously, playing KH changed my life. 90% of those games were beaten after I fell in love with KH.