If you're going barebones, you're obviously an upgrader.
And so, go Intel.
Everyone has been waiting sooooo long for AMD's next generation chips where they promised a 60nm architecture. And here Intel comes, allready releasing a preview of their next gen chips code named "Penryn," which will be coming out in Jan 08, as they release the Q6950 this month, the first of cpu's to introduce Intels 45nm Structure.
45 > 60
Intel's C2D's were 60nm....
45nm = a whole lot less energy, a whole lot less heat, a whole lot better overclocking
They r made with less transistors or som shit n therefor are hella cheap and will be released using the same pricing module as the C2D's. And they'll support the LGA775 cpu socket. And they recently overclocked their stock clocked 2.66ghz beta Penryn chip at the Intel factory to 5ghz at being only slightly overheated with liquid cooling. Easily reached 4ghz w/ air cooling.
EDIT: Also with that said, dont buy from one of those 2. If you're going barebones, look for the new X38/38X chipset motherboards. They support so much more (penryn support, PCI-E 2.0 for those Geforce 9 cards coming out). Or if you really want to wait, som company will be implementing a new CPU socket type for the penyrns sometime middle 2008. And if socket 775 lasted for hella years (4-5?) imagine how ahead u would be with that new socket type, especially as we reach our peak of this computer age.