I've found that Western Digital makes some nice external hard drives, although you need to read the reviews because there are certain models that have had numerous problems, while others have performed flawlessly. Do you know what size drive you are looking for?
Well, going by price it's not much more money for a 500GB drive over a 250GB or smaller drive, so any one of these would be something to consider:
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148404
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136466