Sonic was on Genesis, not SNES, lol.
I vote Sonic. GTA just isn't my cup of tea, and I'm more of an action/adventure/fantasy/RPG (give or take a few genres, haha)
I'm a true fan of Sonic and have been since I remember, and not just an old skool fan - I really enjoy the newer 3D ones. (SA1 and 2 are two of my favorite games of all time. A lot of memories, haha.) Sonic Heroes did leave a bit to be desired though... but it was mostly an action game anyway, and passed the test.
Best Sonic game ever?
Sonic 3 and Knuckles Lock-On. **** yeah.