this is like the most pointless topic ever
I don't have posters, I just have wall scrolls. I have a Vocaloid one of the Kagamine twins, a Sword Art Online one and Attack on Titan.
The only small "poster" I have, which is probably the size of two A4 sheets of paper is of Pinkie Pie's face that I got in some little box that had a holographic card or something in it.