Some folks cry and cry and CRY about WD Hard Drives, but I've got a 500gb one that works like magic. I've been almost all the way around the world and back with my 250gb WD Passport, as well. No fuckups or anything of the sort. WDs are cheap, seem pretty reliable, and all that good stuff. Do they stand up to being banged around? I don't think they would. My Passport seems pretty delicate. Still, I treat all my electronics with extreme care, so that's not an issue with me.
If you want to move around with this much, get an external HD that can get its power off the USB port as well. My 500gb is an older one that has two cables. It's pretty much a huge headache to try and take with me anywhere

I just let my 500gb one sit on my desk at all times, and I'll plug it in to the ol' laptop if I need it.
For stability's sake, look in to an enclosed external hard drive. I've got one that I put all my vital backup stuff on. Supposedly, you can yank off stuff from some higher-end brands after the drive has shitcanned, but I just back up on this enclosure drive. Still, no problems with either WD.
Jam it back in, in the dark.