Viper Lair take a look at Corsair's current speed king.

The Corsair TWIN2X-8500 is a strong performer at both high frequency and low latencies. Basically, depending on your needs, the ram can easily switch between the two options. To be truthful, the main market for this memory is going to be users with 1066MHz CPUs so that they can run their memory 1:1. That said, I think overall you'll see better numbers if you can tighten the timings at the expense of a slightly lower clock speed.

Corsair TWIN2X512-8500 Memory Review