I have a lot of posters! Too many, perhaps! The vast majority of things covering my wall are Pokemon-related, and I've sorted them into collages by type in order to keep things organized.
The first picture shows the wall-hanging-things from Elite Trainer Boxes over the years. I'm getting a new one soon, so I'll have to remake this one, but it shouldn't be too hard. Not a big fan of the overdetailed 5ban Graphics art but the wall hangings are neat.
The second picture is the postcard-sized prints I've gotten from independent artists at conventions over the years! The Mimikyu one is actually sparkly, and it's really hard to get a decent picture of it.
The third one is for compilations of Pokemon- I have a framed puzzle from Gen 1 that I got at a thrift store with the original 150, a circular framed puzzle with a bunch of mega-evolutions that I got at an arcade, and two other normal posters. The Sinnoh one is sort of curled up and also ugly but eh.
The fourth picture is just miscellaneous things- A clearfile folder from Best Wishes I hang on the wall, an ORAS pre-order bonus, an Alola poster I got out of a book, and a Sun/Moon pre-order bonus that I love a lot.
I also really love posters of the Pokemon world. The Galar one is more of a felt banner, but it counts enough. I wish they made a large-scale official Unova one!