Source: marvelcinematicuniverse.wikia.com

4. Batroc the Leaper

And here’s yet another villain who was denied his time to shine. Georges Batroc, aka Batroc the Leaper, is the master of the French kickboxing art of savate. Plus, he owns both the best mustache and worst accent in all of comic bookdom. In fact, he did get a filmed appearance.

That's right! Remember that Algerian mercenary from the beginning of Winter Soldier? The dude on the boat? That was Batroc!!! Also, the boat was the Lemurian Star, a reference to Lemuria, Attuma’s underwater city from the comics. Neat little reference, there.

Anyway, Batroc put up a fight against Cap, but he did wind up the loser. SHIELD arrested him, but he's still out there.

Maybe Batroc, Scorpion, and the Leader can go have a party and be real villains.