Legit Reviews has a 3 way overclocking memory kit comparison, between A-DATA, Kingston, and Mushkin. All of the kits are PC2-6400/DDR2 800MHz, but they all have different timings, and different voltages.  See which of the 3 you like best.

"The Mushkin eXtreme PC2-6400 modules loaded Windows at 1060MHz on the first try. Although we

later found that 1060MHz was unstable this was an impressive achievement. After RST Pro2 testing

we found that 1042MHz was 100% stable on our 2GB memory kit... "

Here are some more Memory articles from around the web:

src="http://www.pcper.com/site_gfx/icon-mem-small.gif" alt="Click Here to go to Memory"

• Hynix:

Registered DIMM and FB-DIMM price parity in 1Q 2007 @ DigiTimes

starts sampling 1Gb NOR flash memory @ DigiTimes

2GB Dual Channel Kit @ InsaneTek

KHX6000 PC2-6000 Memory Review @ motherboards.org