Core 2 Duo vs Core 2 Quad. plz see the details n 4 wat i use my comp. n tell me which 1 is the best?

I'm a home user. I browse a lot n also play many graphical games like Need for Speed n GTA. I also store many fotos n songs n videos. plz tell me which 1 to buy. Which 1 will last longer? n which 1 is better ? n which 1 can be used in the future? Core 2 Duo or Core 2 Quad ? plz hlp me itz really urgent