AnandTech: USB Flash Drive Roundup - 10/2005. The latest roundup. Last time, the Transcend was the fastest, but now we have 100x drives that are more expensive at $100 but incredibly fast.
The two fastest overall are the Kingston DataTraveler Elite and Lexar JumpDrive Lightning. Both really fly because they are "dual channel." That is they have two sets of NAND flash and write to each simultaneously.
