If you play games and do casual stuff, the Pentium G would suffice.
If you are a power user: do a lot of virtualization, parallellprocessing, vido editing, testing.
You'd better be off with older, but more suited quad core.
I myself prefer older quads to newer i3's and similar products. Reason being that I need more cores over clockspeed, and I don't play as much as well, and 2.66Ghz should suffice for my little gaming needs.
Plus. Used quads are dirt-cheap.