I run an Athlon CPU, and this will probably surprise you to hear that i'm going to recommend an Intel P4. At the moment, Intel have the upper hand in the CPU speed market, but they cost a fortune to buy seperately compared to AMD. If you're buying a ready built PC though, you can get some P4 bargains at the moment. Also, AMD processors run very hot. They take a lot of cooling, you can spend ages trying to lower the ambient temperature of your case, installing various fans. Pentium 4 need less cooling, and are faster. So which would you choose? I built my own PC, and i chose an AMD processor simply because it was fast AND cheap. :)