Source: marvel.wikia.com

7. X-Factor Investigations

Jaime Madrox, aka the Multiple Man, was a fun and charming X-Men character who hasn't really had a ton of time in the spotlight.

His only notable film role was in X-Men: The Last Stand, which is a movie that does not exist. I mean, he was the only good part of that movie that does not exist, but it's still not a great claim to fame.

Madrox, whose power is that he can clone himself when he absorbs kinetic energy, was the founder of X-Factor Investigations. The office was home to a kick-butt team of little-used X-Men, X-Force, and X-Factor team members, including Strong Guy and Wolfsbane. The series ran quite a while, and gathered a large number of devoted fans. My personal favorite arc involves Madrox hunting down some of the dupes he'd lost track of.

I know Fox is kinda focused on the Deadpool corner of the X-Men franchise right now, but a charming little detective film wouldn't be unwelcome.