Check out some Prince Jammy/King Jammy (same person), he does some great dub. If I get a chance I'll post up a track tomorrow.
There's an album produced by Scratch Perry from a cat named Max Romeo called "War Ina Babylon" which is a dope ass album.
I think Nuttkase pretty well laced you with the essentials, but there's a group that I've posted before called The Royals who are real creative with their dubs. I'll try to post up one of their tracks tomorrow, too.