I have several old rubber armored flashdrives made by some no-name company "A-Data" (or something like that). I don't remember HOW long I've had them, but they are 256Mb and that was considered large at the time I bought them. That holds all the emergency personal info I need. I encrypt the data with TrueCrypt and have the executabel for that stored on the thumbdrive as well. Some of them have gone through the wash and dryer a couple of times, with no ill effects. I wish A-Data still made them. No-name or not, they have been 100% reliable and bulletproof

For non-armored thumbdrives, I use 8Gb SanDisk Cruzers.