I can also vouch for the Rosewill/Samsung setup as originally suggest by Cave Man. I have 4 of the Samsung drives and all have worked quite well for me. The Rosewill enclosure has been nice as well, though I have had issues with FW using Vista 64 for writing (not the enclosure/drives fault, works fine in OS X, reads in Vista 64 are good, writing is ridiculously slow).
I also have a WD Passport Studio which works well (again FW 800 issues in Vista 64 though; USB is as expected). I currently have it formatted with a FAT 32 partition for Scratch which I can convert to HFS+ or NTFS if needed, another Fat32 partition for portable media storage, a third partition formatted as NTFS for Vista specific writing storage and a fourth partition for HFS+.
Also, Windows XP 32 can't understand GUID partiton tables. If you're using Vista you shouldn't have a problem, but thought it worth mentioning just in case since a lot of people still use XP.
I also have a WD Passport Studio which works well (again FW 800 issues in Vista 64 though; USB is as expected). I currently have it formatted with a FAT 32 partition for Scratch which I can convert to HFS+ or NTFS if needed, another Fat32 partition for portable media storage, a third partition formatted as NTFS for Vista specific writing storage and a fourth partition for HFS+.
Also, Windows XP 32 can't understand GUID partiton tables. If you're using Vista you shouldn't have a problem, but thought it worth mentioning just in case since a lot of people still use XP.