OP here, let me clarify a few things. It's not enough to me that it be an amusing poster, I have to have seen and loved the movie.
It's also not enough that I love the movie, there are plenty of movies I love with posters that do nothing for me. Even some of the ones I've posted don't really work for me. Dark City is one of my favorite movies, but the poster does nothing for me. I basically posted it entirely from personal bias.
So for example, this Sharknado poster while funny wouldn't work for me as I've never seen the movie and likely wouldn't love it.
I posted Redline for the same reason as Dark City, its a gorgeous film, but that poster is bland. Same problem with most of the Willow posters, loved the movie as a child, but the posters are kind of bland. I think Raimi's Spider-Man 2 is one of the best superhero movies ever made, but the poster is awful.
What I've kind of ruled out are the Deadpool posters. When it first came out, I reasonably enjoyed it, just on the level that it felt very accurate to the comic. Since then it's left less of an impressive taste in my mouth, and news of changes made to the sequel have kind of soured me on it retroactively.
On the other hand, Godzilla vs Megalon is up there for totally personal reasons. First, the poster is ridiculous and depicts a scenario that never happens in the film, second it's actually the very first movie I ever saw when I was three years old.
I really liked Winter Soldier, I like Captain America's shield as an icon. I watched Nightmare Before Christmas like 800 times when I was a kid. It would be nice if the wall had a little touch of sex appeal, and to fit my tastes that would best be filled by either Elvira or this Michelle Pfeifer poster.
Iron Giant would mesh well with both The Rocketeer and Robocop. If I have more space for it later, like an actual theater room or whatever, Rocketeer, Iron Giant and The Shadow would work very well as a set I think.
Objectively, Army of Darkness is the best poster in the lot though, and I'm leaning towards it heavily, it's just a question of whether or not it meshes with the others.