The CPU choice was really the first choice I made, and it was the driving factor to convince me to build my own rather than buy a pre-built system.
I try to be pragmatic about my choices of CPU and look for good value for the level of machine I'm trying to acquire. The last two times I've been in the PC market, AMD was the value point of choice. This time around, though INTEL is the move and shaker. They 805 Core is priced very attractively ($111.90 at Newegg as I write this). It doesn't have all the features of the Extemem Edition chips, but it is DUAL Core and is one of the easiest chips to overclock. It also has a lot of headroom for overclocking (see article).
It is not without it's flaws, INTEL has disabled some of the fine tuning features for overclocking, and it can run hot, especially if you begin increasing the voltage.
While I want to overclock to get better value out of my expenditures, I am not going to push the technology to its limits. So, for this system, the combination of low price, large overclocking headroom (with plenty of internet stories of successful overclocking) and dual cores make this a great value cpu.
AMD has some attractive chips but for a change INTEL is my value leader. So, choice made.
My philosophy on PCS is to make all of my decisions in a tight time frame and then move. It's very easy to get caught up in the spiral of new things that are coming and never move. On the flip side, I try not to overinvest in my PC's because next months model will be significantly faster.
More Component briefs to come....