The Techtools article would be a great read. In fact: http://djtechtools.com/2015/01/11/digital-crates-what-are-the-best-flash-drives-for-djs/
They recommend some pricey drives, but just keep an eye on any store that sells this kind of item. I found a deal on a 3 pack of Sandisk Cruzer U USB drives (Each for the major softwares) and just bought another for pure mp3s so I can play on any computer/CDJ I might come across along my DJ journey. That doesn’t mean I won’t be on the lookout though in case I come across a sale of any from the article. (All are 16gb, USB 2.0)
One thing I will echo from the article is to NOT BUY GENERIC DRIVES! I ignored this as the price and form factor was great, but the read times were deplorable. Sometimes a track would take 10-30 secs to load which is unacceptable for DJ purposes. So in short, spend the extra dollar(s) and get drives from a brand name. It’s worth it.