Single room all to myself! How do I make it worth showing off?

I've got a single room lined up for next year at college. The room itself is in a building that's very old, and no amount of renovation can get it past the point it's at- it's hit the old-man stage of buildings and I want to make my room an exception to this rule. I'm a 20 year old dude, and any advice on making the proper college man cave is appreciated!