Some humans use posters as a means to idolize heroes they wish they could be. Have you ever had a Comic related poster hung in your room? If so, what was it of and up to what age were you when it finally came down?
I have a poster from the movie Ghost World (which was based on a comic by Dan Clowes). I got the poster a few years ago and put it in storage just last March.
As far as any other comic characters, I never had any posters. Around the time I was pretty heavy into superhero comics, many of the more popular books were reduced to overemphasis on character drawing and less on action connecting between panels. Instead of using pictures to tell a story like Will Eisner did, they'd draw these really well-colored static characters flexing ridiculous numbers of muscles (See Michael Turner's Fathom, Campbell's Gen-13, or most X-[Insert Name] books for examples). Pretty to look at, but not great to read.
My point: if the entire book reads like 20 individual posters, I probably didn't need another with which to litter my walls.
The only poster that comes to my mind is one of Spider-Man that my cousin drew for me. He was really a great illustrator and it was worthy of being hung on the wall. By the time I hit my teens we had moved so much that no poster could ever survive very long.
I had many when I was younger but the biggest of them was an awesome Spiderman poster I had.