western digital passport all the way! dont listen to the haters. i’ve had 6 wd hard drives: 3 passports, 2 my books, and a terrabyte non-portable drive. the only one that broke was my own fault after dropping one of the my books from about 4 feet while it was plugged in. I have dropped my passports a few times and have not had any problems with them tho. I would definitely recommend a case for them anyway. either way staples has them on sale right now http://www.staples.com/office/supplies/p16_Western-Digital-500GB-My-Passport-trade-Essential-trade-Portable-Hard-Drive_247997_Business_Supplies_10051_true_SEARCH for 120
and if you buy an e-junkie coupon from the e-junkie webpage (you pay through paypal so its secure) you get a $25 off $100 coupon for like a buck or two making it a real cheap buy for a 500 gb portable drive. I just picked one up at this price earlier in the week, plus it ships the same day for free so you’ll have it in a day.
if you dont feel comfortable using e-junkie tho amazon has them for like 117 with free ship too. These drives are great. I and a few of my friends are all about them.