What processors can I upgrade to?

I currently have a Pentium Dual Core E5800. I checked online and it said it was a Socket 775 processor slot. Can I upgrade to a Core 2 Duo processor? Can someone also give me a list of processors that I can upgrade to? I was hoping to turn my computer into something more capable of running games. Btw I have a Dell Inspiron i560 565-NBK.