5. Green Lantern
Ryan Reynolds was actually pretty good as Hal Jordan, leaving behind much of the silliness he had brought to other roles up until that point to make the character more than just another wisecracking Hannibal King/Wade Wilson type hero. Unfortunately, a solid performance from the Deadpool star wasn't enough to save this trainwreck, and there are just so many things that Warner Bros. got wrong with this superhero. The costume is obviously a good place to start, because while the fully CGI outfit certainly looked better in the final product that it did in the trailers, it was a major misfire which definitely didn't do Green Lantern's comic book look justice. That's a superficial problem though, and the fact that Hal was such a poorly written character with a story arc which had lots of predictable plot beats but no meaningful moments was a shame. The movie just consisted of watching him go from Earth to Oa and back again as he casually adjusted to being inducted into the Green Lantern Corps, trained, and taking out the most powerful threat they'd ever faced with relative ease. Green Lantern many have hit all the important plot beats from the source material, but forgot to make Hal matter in his own movie, and so it's no wonder the character remains on the shelf.