i like western digital but they tend to put 2nd rate hds in their external products.
personally i prefer to build my own since it is super easy and you know what drive is going inside. it tends to cost a bit more to do this but you also have more options if either the case or drive gets toasted.
recently i put a wd caviar black 640gb (performs better than 1tb) in this aluminum
enclosure. pretty rad. go with the green wd model if you want a massive drive or you may have power issues.
vantec enclosures are good if you are more of a pc type guy.