What's Gran Turismo going to do? Be another show case for hundreds of useless clone cars? Gt3 was ****ing awesome. Gt4 sucked. Horrible interface, engine sounds were atrocious, AI was stupid, lack of damage, extreme bias in car power and ability. It was ridiculous. GT3 still remains one of my most favorite games, though.
PS3 has some awesome games coming out. LittleBigWorld, Home, Ratchet & Clank, Heavenly Sword, Lair, Metal Gear Solid4. The console packs a serious punch, but the 360 is capable of running games in 1080p THROUGH component cables. The fall patch made 1080p work, and the list of games supporting it only grows.
The 360 has its problems, but I personally have not had any, nor has anyone else I know who owns one. I only know one person with a PS3, and it's been fine for him as well.
The online on 360 destroys the PS3 online. inter-game voice chat, join games just from clicking on someone's name. All very seamless. The addition of paying for an account makes it easier to drop the ban hammer on douche bag hackers. Halo2 was bad in that regard, but MS isn't playing this round. Modded consoles detected on LIVE get a nice perma-ban.
Both are getting great support in the future. Going into college, and money being an issue, I'd suggest the 360. The price difference will allow for 3 games for the 360.