I would have liked to see a Warcraft movie that was self-contained, small in scale and was set during WoW rather than the Warcraft games (for as much as I love the RTS games, they're not the thing most people fell in love with when it comes to Warcraft as a franchise).
My ideal Warcraft movie:
A small group of Alliance and Horde raiders band together to defeat a Classic WoW Boss (ex. Onyxia, Ragnaros, Kel'Thuzad, etc.).
A simple story that focuses on character relationships and doesn't require massive lore/exposition dumps. Most people don't need races like Dwarves, Elves, Orcs, etc. explained to them because so much of those elements exist in broader fantasy.
It should incorporate everything people love about WoW: Alliance/Horde, different races/classes, exploring the world of Azeroth, working together, and defeating powerful bosses.