I've used DupeCoop CD/DVD Duplication in New York City serveral times now. I will never go anywhere else. They help you with your artwork, and are very helpful and knowledgeable. And then turn jobs around quickly. Surprisingly, even with this kind of personal service, their rates are fantastic.

They are different than other duplicators in that they design your package from text and artwork you provide. In my case, they emailed a pdf of the setup for me to check out and make changes. And it's a lot less expensive than going to a designer. The final package is beautiful.