I went with the Core 2 Conroe, which was by far the cheapest, and got my overclock stable around 3. Be sure to include Zalman CPU fan if you are doing this though. I think in your top (i.e. cheaper builds) you should go with the lowest end stuff. I'm beating 99.3 percent of everyone in servers in BF2 with my current setup.
If gamers really want to do it right, especially in online games like BF2, where load speeds are key to you getting in those jets, choppers, tanks, etc. You should get 2 Western Digital Raptors RAID 0 Striped, solely running games, then have something like a 320 GB Caviar (which HDD's right now are pretty low priced at around 120 Bucks), running windows. If you want to go more hard core, partition the Caviar (or similar SATA drive) 3 ways, having WIndows, Programs/apps, and Media (mp3's, Wav, mp4s, etc.) as the partitions.
Works like a charm
Or, if you are cheap and don't want 3 hard drives, Just buy one raptor and put games on it, and then like a 80 GB hard drive. Those are probably around 50-60 bucks right now.
I'm the king of "bang for the Buck". .04 milliseconds is never worth 300 dollars to me. I follow slightly behind the tech curve always.