Everything Gyrene says - well, almost.
I'd avoid AMD and go Intel, but I'd stick to ATI over NVidia as he suggests.
Why? I love AMD from the point of view that they keep Intel honest (or more honest, anyway) with competition - and I was never happier than late last decade when they were beating Intel like a red-headed stepchild. And while their processors do not fare well in a few odd corners compared to Intel (like video processing extensions, for example), overall, they are exceedingly capable. So why do I avoid them? The simple answer is that even today, the chipsets support of AMD is often "hit or miss", and if you get a combo that's great you're golden. But about 1/2 the time, you get a squirrelly little beast instead. I fought my wars with AMD systems that worked 99.5% around the 2004/2005 time frame, and have no desire to go there again.
Nvidia... at one time I'd buy nothing else. But they have become the new IBM of the late 80's and 90's - suffering from a serious case of overconfidence while putting out a product that their competitor's beat all hollow on almost every important front all while focusing on marginal markets rather than their mainstream "bread and butter".
I built my new system (Geez, almost a year ago, how time flies!) on an LGA775-based board - It was less expensive and just as capable, and I honestly believe that by the time it's time to upgrade I'll be looking at end-of-life for 1366 anyway (which is still more expensive, although the margin between has shrunk since my build.)
ALL IMHO, take it for what it cost you....
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