If Green Lantern had been done right, it would've most certainly been a top-tier movie property.
We should count our blessings that the proposed GL movie with Jack Black never made it out.
To answer cube_b3, yes, the Green Lantern movie was bad. It might be acceptable for kids, but everybody else will be sorely dissapointed.
GL is a comic book about outer space adventure. It has more in common with Star Wars, Flash Gordon and all that. But with this, they seriously attempted to slightly emulate Thor, but came out crooked.
The movie fails not because of the superhero himself, but because the movie barely takes place in outer space and what happens on Earth, a lot of it is boring and underdeveloped. The only time the movie is good is when Hal uses his GL powers, especially in the final act.