We put up a single shelf above the television, which did a stupendous job of eating up some of that annoying free space lingering on the wall. Unfortunately this doesn't solve the problem of what to do with the rest of the empty walls.
Ideally I'd like a HUGE piece of artwork to hang just above our heads while we are on the couch. It would be visible as you walked into the apartment and while eating dinner at the dining room table across from living room area. It's hard finding brown-based paintings that don't have tons of green and red in them. Our apartment is most definitely blue and brown --- the only red that peeks through is the red in the vintage Star Wars poster found in one corner. (The Man Corner)
Another obvious option is just purchasing some nice frames and putting photographs up. The problem with this is -- we're just not photograph-loving people. Despite being together for 4 years, I can count the number of pictures I have of Matt and I together (and BOTH look great in) on one hand. I'd have to diet, wait for my skin to clear up, grow my hair out, and wait for upload times just to decorate my apartment. Not going to happen.