I recomend an X2 dual core or an Opty. Optys are supposedly good OCers, but I've heard good things about the 3800 and 4400 for OCability. I love my 3800, it gives great bang for the buck. Yesterday I was doing e-mail, web browsing, a virus scan, downloads, and a bunch of other thigns in the background, with no noticable slowdown on any of them. Definately quite nice.