My mind instantly sees your window behind the TV as a design wall. Many ways to make that but the cheapest.... get the largest flannel backed tablecloth, with a color u love, sew ribbon in the top corners so u can roll it up and tie it closed when not in use. I have a small tiny space and thats what im making for over my paintings on the wall. I found the tablecloth at the dollar store. I do like the ping pong table idea alot too!! So many great ideas!