Dreams resort in Puerto Vallarta was a great all-inclusive that the Mrs. and I went to for our honeymoon in 2009.
They have a private beach that is bordered by cliffs on either side, so they are easily able to control the vendor traffic on the beach. I don't remember having any complaints about the service in general, and the wait staff at all of the restaurants was fantastic.
There were several restaurants at the resort and they all had great food, although none of them understood that sour cream is supposed to be sour (minor issue). Any dish in the restaurants that had Oaxaca cheese was incredible.
The Mrs. and I were there for our honeymoon in June, so the resort wasn't terribly crowded. It was rainy season then, but the weather only caused an issue with our plans one night. One issue we did run into was that there were sting rays in the ocean a couple of the days while we were there.
Having been to both Puerto Vallarta and Cancun multiple times, I have to say that I like Puerto Vallarta more. It's smaller and feels less touristy, and is also surrounded by more foliage.
It wasn't a terribly detailed description, but hopefully this will help with some of your early research. Best of luck!