I'll second the LG GSA-4081B - details here:
http://www.lge.co.uk/mod_perl/go.pl/...tegory_uid=648
I have the 4040B which is its predecessor and it seems fine. Note however that these drives only supports bare disks and not those in caddies.
If you only want to read DVD-RAM disks on the PC then look at the Panasonic drives - some of their DVD readers also support DVD-RAM.