me too have good luck with AMD. Though support for AMD 64 is comming to linux mce and is not yet there... as I am waiting for it myself.
BTW using AMD64 you can have up to 8gb for memory, something you may want to have when doing encoding/watching and other stuff...
But intel got a 1 year head start when it comes to quad core. AMD release it only couple of months back.. I am using AMD 6000+ (dual core cpu) and it has been cool. Though the real test would be to decode mpg4 (H.264) streams.