running a p4 at 2.4 ghz. its an older model, doesnt do hyperthreading and is only on a 400mhz bus. i really have no preferances, you get what you pay for. the only amd i used was a low end duron 900mhz and it was a good economy chip. it was to slow for me and i upgraded to a 1.7 ghz p4 (which sill resides in my closet somewhere) and a new mobo to boot. when my laptop got fried its prosessor was still good and thats the one im using now.
from what i know, amd does have a better bus archetecture and gives you some better options when it comes to chipsets (nforce for example). im planning to build a new pc somethime in the next 6 months, and i think il use a 64 bit amd. need to do more resurch because i dont know jack about amd's current line.