To your question "what is the best retriever training DVD?" the single best retriever training DVD I have ever seen is the collar conditioning DVD from Mike Lardy. I've got all of his DVD's (first DVD version), Mertens, Rorem, Farmer/Aycock, Stawski, some of the Smartworks DVD's, some not worth mentioning and I've seen several other retriever DVD's but Lardy's CC DVD was the best one (for me) hands down. I probably wouldn't have tried to CC my dog on my own without it.
The only puppy DVD I've seen is Sound Beginnings and I would recommend it.