The odd thing, is the oldest USB flash drive I have is still the fastest one in the collection here. It sustains about 28MBytes/sec writing, over USB2. And that 2GB device is close to 10 years old now. I forget the brand/model, and it was discontinued years ago anyway.

I have a ton of newer, slower sticks around, many of them freebies. Of the modern-ish ones, I've got a couple of Sandisk Cruzer drives (very retro stainless styling and a slick click mechanism) that manage around 20MBytes/sec writing.