We hope that you are routinely backing up your digital photographs and other files. If not, you might want to take a couple of minutes and watch this video from David Bergman at Adorama TV. We can't encourage you enough to put a solid backup process in place to protect all those digital memories.
If you're looking for a suggestion on external USB drives to use for your backup, we have had great luck using Seagate drives. Just make sure you get one large enough to store all of your images. Remember to also pick one up to use for your offsite storage.