Debuted: "Tales of Suspense" #52 (1964)
Previous Movie or TV appearances: "The Marvel Super Heroes" (animated), "The Super Hero Squad Show" (animated), "The Avengers: Earth's Mightiest Heroes" (animated), "Iron Man: Armored Adventures" (animated), "Avengers Assemble" (animated), "Ultimate Adventures" and "Ultimate Adventures 2" (animated), "Iron Man 2," "The Avengers"
Why: Given that the majority of her Avengers teammates (save Hawkeye and Nick Fury) have already been the subject of their own solo movies, it seems about time Scarlett Johansson's Black Widow got her moment on the big screen. So what's the hold-up? Well, for starters, she's a woman in a male-dominated sub-genre, and secondly her name value doesn't have the quite the same heft as compatriots Thor, Captain America Iron Man and the Hulk. Nevertheless, with fanboys hungry for seemingly anything "Avengers"-related in theaters these days (who'd have thunk Iron Man of all superheroes would prove to be such a huge attraction when the first film debuted back in 2008?), giving Black Widow her own standalone silver-screen adventure is pretty much the biggest no-brainer on this list. Luckily, Marvel Studios president Kevin Feige has hinted at a Black Widow solo flick in the past, so hopefully we'll be seeing one come to fruition in the not-too-distant future.

- Chris Eggertsen

- Gregory Ellwood