Just because I like to argue with Nickname (from Anandtech, who I now believe to be reliable since my CPU subscription):
“For now if you are looking for the very best overclocking memory you can buy for your new rig, then Corsair Dominator PC2-8888 should definitely be on your list. So should OCZ PC2-9200 Flex XLC. Both memories provide remarkable performance and push DDR2 performance to new levels. The absolute fastest memory tested is definitely Corsair Dominator DDR2-1111, which reached DDR2-1315 at 5-5-5-15 timings and the even more remarkable DDR2-1233 at 4-4-4-12 timings. If your platform will be 680i or 650i then Dominator is your best choice. OCZ Flex XLC is a bit slower at DDR2-1300 on the same platform, but it is also an excellent choice.”