Guy Gardner
Hal Jordan became Earth’s first Green Lantern in the comics (and in the movie) when the spaceship of Abin Sur crash lands near him. But if Abin Sur’s ship had been on a slightly different trajectory, the green power ring might have gone to Guy Gardner instead. What’s the big deal? Well, despite being brave, skilled and committed to the Green Lantern Corps, Guy Gardner is also arrogant, childish, narcissistic and quick tempered; not exactly the best superhero material. Still, Gardner has regularly been a part of the Justice League line-up since the mid-80s, despite the fact that he’s rubbed just about every member of the team the wrong way.
So, how can Earth have two Green Lanterns? In the comics, Gardner becomes an auxiliary Lantern, a back-up for Jordan who manages to prove his worth as one of the Corp and becomes a more permanent part of the Green Lantern starting line-up. As part of one incarnation of the Justice League, Gardner managed a complicated work relationship with his fellow heroes, although he did try to start a fistfight with Batman, which was either ultra-brave or foolhardy (and given the fact that the Dark Knight knocked him out with one punch it was probably the latter).
Still, Guy is dependable, loyal and fierce in any fight, whether it’s against the Superman-killer Doomsday or the reality-bending Parallax. It’s pretty unlikely that a Justice League movie would recruit the Ryan Reynolds incarnation of Green Lantern for the film, but you do need a Green Lantern on the team, so why not go with Gardner?
With his take-no-prisoners attitude, and ends-justify-the-means world view, he goes against the superhero type and would be a natural foil to the rest of the team. More specifically, Gardner would have real friction with Superman, who would likely be leader and lead character for the League. If the Man of Steel represents the fine, upstanding positivity of America and the American experience, Gardner is the jingoistic “ugly American” stereotype come to life.
In other words, Guy makes a more complicated Justice League, not to mention one that’s a little more dysfunctional, too.