fire emblem heroes except when you buy a ticket the attendant pulls from a random marble dispenser and you only have a 3% chance of actually seeing the decent 5 star version of the movie
I think a Kingdom Hearts movie could be interesting, the cut scenes already look like gorgeous movie graphics. It would also make the franchise more accessible, I love the bits and pieces of the games I've played, but at the same time, I just don't have the money to buy such a wide variety of consoles, or the patience to get through some of the harder parts of the games, so I've never actually been able to play through all the games (or even 1 and 2, the only game I ever completed was 358/2 Days).
Anything by Blizzard, really. Their animation studio is very talented already, so I think a movie by them could definitely work.
I think a Metroid movie could also be good. I'm not sure how likely it is, but maybe it could happen depending on the success of the Mario movie. I'm not getting my hopes up though.
Speaking of the Mario movie (if it even ends up being made), I don't have high hopes for it. I'm not surprised Nintendo chose Mario as he is their most iconic character, but he is probably the worst Nintendo character to base a movie on. Mario games are fantastic, but not for their "gripping" story.
In terms of live action movies? Nothing. As live action movies based off games are always terrible. The best thing to come out of a live action game movie is the mortal kombat theme.
Animated movies? EVERYTHING. Animated game movies are normally amazing, so I'd be happy to see any game made into an animated film.
For example take resident evil, the live action movies are B grade and not very good (they're amusing but that's about it), then you look at the animated movies and they're so much better cause they're like giant good graphics cutscenes and they normally stay true to the game a lot easier.
Super Smash Bros. The Movie, with a plot with more twists and turns than the endgame for Brawl story mode.
EDIT: And yes, the characters would all talk with their personalities and interact during the movie, not like in Brawl where they basically react with gasps and act like they are literally mute (LOL).