Build a PC, CH style. Once upon a time people sold books on how to do this. Now there are blog posts that do a better job.
I'll probably never build another PC, but the example and parts list are good references in case I change my mind.
PS. CH has about 3,000 bloglines subscriptions. Wow, to think I knew him when he was starting out... (This blog has 2 subscriptions, and at least one of those is mine.)
Update 7/11: Part II. I liked the comment about drivers that come with the mb - toss 'em.
Update 7/24/07: CH has a cumulative summary and a set of suggested configurations.