I'm in need of a decent USB flash drive for school. I never really used one, as I always used things like Dropbox to store files so I'd never lose them. However, the classes I'm taking apparently require one, so would you guys suggest something good? I'm looking for something with a fast read/write speed (at least 20MB/s), around 16-32GB of storage, and won't break if I were to drop it a couple of times. My budget is $100. Any suggestions would be great.