I've been a fan of Super Smash Bros. since Brawl. After watching the fanmade live-action series Mario Warfare, it got me thinking of a Smash Bros movie. It should be build up as part of a series of continuity films, like The Avengers. They should come out with several movies of the Nintendo video games, leading up to the big Smash movie, followed by more films for the sequels.
First movie lineup:
Following with several characters appearing, like when introducing Hawkeye and Black Widow. I'm thinking R.O.B. and the Pokemon.
I don't how they will all meet up at the moment, but I'm hoping the movie would be awesome if they ever decide to make one.