You might want to trade most of them, such as older versions of FIFA, NFS and such.

However, I would keep a hold of your favourite ones and certainly GTA VC. I miss that game so much! And after playing GTAIV, I want to do that game again.

Plus, have you considered using an emulator to play your PS2 discs on a PC? It's not piracy if you own the game. (getting the BIOS might be illegal though...)