Basement decoration advice?

I need to make my basement look cool. It has bare cinderblock walls, a plywood ceiling with airvents exposed, and cement floors. In the main area is a nice couch and a nice love seat, a rug covering the floor, and hot water heaters next to it. There's a ping-pong table and a bunch of boxes. I mean a LOT of boxes... the stairs are wooden and in the back is weight machines. It's really kinda ugly... what can I do to decorate it? So far I've got adding carpet and a drop-down ceiling. Imagine Eric Forman's basement in That '70s Show but with a weight room. It's pretty bad. Help is appreciated, thanks.