VGA Charts - Comparable Video Card Benchmarks
CPU Charts - Comparable CPU Benchmarks
PriceWatch (not as good as it used to be, but useful)
Because my current computer is really noisy, I put a little bit of time into reasearching quiet fans and such. Silent PC Review came in handy for that. There's a forum sticky that goes over the basics, but there are specific reviews available, too.
I thought I could come up with more links than this. It's a start.