I went with Forgotten Realms for the setting, but really, I'd be fine with any of the published settings. If you look at the first movie, one of the things contributing to it feeling like a bad campaign run in a bad homebrew run by a bad DM was not using D&D IP. No one gets warm fuzzies from hearing the names Izmer and Sumdall. Whereas the second one has references to things familiar to gamers, like the Barrier Peaks. Now, the average non-D&D-playing moviegoer might not know the difference, but they can still tell when something has history and cohesiveness. Just look at the difference between Lothlorien and whatever the name of the elven kingdom ruled by Tom Baker was.