We've had pretty good luck with about everyone we've licensed from but I really like dealing with
http://www.xxxcontentdirect.com
It helps they are local, but they also are extremely good with customer service. They're always letting me know when they have something I'm looking for, don't have any problems with replacements on a bad DVD and deeal with quality studios so we don't spend a large amount of time changing out crap quality DVDs.