Depends if I'll be able to travel back in time to experience it again.
Tales of Symphonia was a masterpiece, however the graphics haven't aged well. And now that I'm barely starting to watch anime I realize that many of the characters in that game are uniquely generic. ( Kratos Auron is the best! )
I still love Symphonias use of angels. I think that lead me to follow a certain belief , away from all religions.
So to answer your question TC. Tales of Symphonia. Definitely tales of Symphonia.
GT: KryDamoure .............I'm a very shy guy *blushes *.......
Only one. To The Moon. I would honestly keep replaying that game over and over. Only problem is you know the story after the first playthrough. :(
I found it a bit overhyped. Better story than most games tend to have and it was nice for a game to explore such different subject matter, but I didn't come away thinking it was amazing or anything - just a game with a decent story.
I guess the games that spring to mind for me are story based. Spec Ops: The Line and KoToR would be nice to play through for the first time again. Maybe the original Halo; I don't remember my first playthrough really.
I wouldn't want to wipe my memory of ALL the games I've played. I don't want to experience FFX again. I would wipe my memory of the following just so I could experience that first time feeling:
Game Boy Pokemon Red/Blue SNES Super Mario World Megaman X 1-3 Chrono Trigger Final Fantasy 5 & 6 N64 Super Mario 64 Wave Race 64 Conkers Bad Fur Day Banjo Kazooie Goldeneye Perfect Dark Rayman 2 PS1 Final Fantasy 7-9 Final Fantasy Tactics Megaman X 4 Megman Legends 1 & 2 Chrono Cross Fear Effect 1 & 2 PS2 Shadow of the Colossus Beyond Good and Evil The Bard's Tale Xbox Gauntlet: Seven Sorrows Morrowind 360 Mass Effect 1-3 Dark Souls PC Commander Keen 1-6 & Dreams Quest for Glory 1 & 5 Kings Quest 1 -3 & 5 Leisure Suit Larry 1-7 Starcraft Diablo 1 & 2 Everquest Discworld Raptor Call to Shadows Hocus Pocus Alien Rampage Ozzy's World Encarta's Mindmaze