2.6 GHz P4; works great. My machine has lasted me four years so far, and I'm trying to make it last for another four! As long as I can play Counterstrike and get things done it's all I need!
I have an AMD Athlon 3800+ in my computer right now, but I will replace it with an Intel Core 2 Extreme Quad G6850 - the ultimate gaming/everythingelse processor!