Remember never to use flash drives as storgae for the only copy of a file. Flash drives are easily damaged (physically, or by magnetic fields or electrical peaks) or easy to lose. Use them only to keep copies of files to hand or for transferring files about.
Considering how easy they are to lose, consider encrypting your drive if using for personal files: instructions for encrypting your USB flash drive.
If for are looking for a USB flash drive, SanDisk are reliable and are good value when comparing quality, design and price.
Some Amazon.co.uk links for connivence
SanDisk 8GB Cruzer Blade USB flash drive
SanDisk 16GB Cruzer Blade USB flash drive
If you are working across Mac/PC and need to format to FAT32, you need to stick to 4GB max: SanDisk 4GB Cruzer Blade USB flash drive