The pantheon of races and monsters in D&D makes for a great setting for stories. That's how you had worlds like Greyhawk and Forgotten Realms and novels based on this stuff. Or planar travel and spelljammers. So much material. There's no reason you can't have good movies placed in these worlds.

I'm working under the assumption that a D&D movie, just like the terrible one with Jeremy Irons, would just be a D&D movie, and not a Forgotten Realms, Greyhawk, Eberron movie or what have you. And the generic D&D setting, what 4e called "points of light" is as vanilla as it gets.
I grew up on those novels and have always had a soft sport for the war of the lance story line. Heck, imo the dwarven nations or evlen nations triolgys would be good movies too, but that opinion is probably not wide spread.