This would be nice, but you have to be careful with a science fiction genre like this. If something similar is already known it will put the audience and critics to sleep.

Metroid would be cool but really difficult to pull of for not being another 08/15 space movie with monsters. And so far, it is very similar to aliens. 

Every movie will have its own risks, that's why deciding who will make the movie will be the most important decision.

That said, I still think that Metroid would be a good candidate because it's one of the few Nintendo IPs that has a good story that spawns through most, if not all, the games. And yet, few gamers know the first steps of Samus and how she became the most famous bounty hunter of the galaxy. It doesn't have to be a movie about monsters, but the growth of Samus from an orphan to a hero.

Well, certainly, but you have to look at this from a perspective of a clueless audience.

They will ask: Why should I watch this movie? What makes it special?

What made Metroid stand out as a game was the emptiness in the early games. You were alone on a foreign planet filled with strange deadly creatures. That's something you can't bring into the movie.

Trying to establish a new movie franchise even if it is well known for gamers will be really difficult.

For Mario and Zelda, I would go as CGI kids movies. No live action.

Nintendo has said that they aren't interested in live action movies, so that option is out of the question.

As for why should they watch the movie, there are two reasons to do it. One is the name of the studio behind it (everybody will go to watch a Pixar or Dreamworks movie, for example) and the other is that parents will take their kids to the cinema to have 90-120 min of peace .

Lastly, you don't need to fully recreate a game in a movie. As I said, you can explain how Samus became a bounty hunter and how she got their suit and ship and, after the movie finale where she "revenges" from the deadly ship of Space Pirates that attacked her, she lands with her damaged ship on a strange planet where she founds an emergency message, puts her helmet on, and decides to explore the planet in order to find who send the signal and help them...

...which would be a good oportunity for Nintendo to launch a new Metroid game that starts just at that point.

Mario and Smash sure, but if Harry Potter and Peter Pan and Lord of the Rings can be done well in live action, I don't see why Zelda couldn't. 

I don't really see a Zelda CG movie working anyway unless it was reframed as a comedy/spoof type of thing ala Shrek, there aren't really any "serious" CGI movies, they're all family comedies, I don't think that would work for Zelda (I guess they could bring back the "excuuuuuuuuse me princess!"). 

They should start with Mario CG movie, lead that into a Smash Bros. CG movie, and if those two are hits, then I think Nintendo would have some experience and could move beyond just animation. 

A live action Metroid movie is what I want, but it's not happening. Sigh.

I think just going with a cgi Super Mario would be a good start to go. I mean, everyone knows Mario. Who'd wanna pass on a movie starring Mario? Seeing Luigi, Peach, Bowser and all the other characters on the big screen in a movie would be pretty awesome.

As for who would direct it, I dunno... I don't know directors very well. Maybe the people who made the Wreck It Ralph movie? I thought that one was pretty good...

I hope it's something like Fire Emblem. I'm hoping they adapt the Altea saga.