AMD Athlon 64 3200+ 2.0 Ghz(single core)
Pentium D(Dell XPS 400)(dual core)
Intel Core 2 Duo E4400 2.0 Ghz(dual core)
Intel Core 2 Extreme QX6700 2.66 Ghz(current CPU)(quad core!)
before all those CPU's i was mainly a console gamer, which is why i don't have a long list like most.