If big statements on the wall aren't exactly your thing, sculpture is another road to travel. While they may not be the best choice for kid spaces or teency-weency apartments, they're a great way to introduce a new shape into an expansive room.
When I first got Kelly Wearstler's book, "Modern Glamour," I took notice of her use of organic shapes to break up rigid lines. If you're like me and like things to be linear, a horse or dog statue is an excellent way to break up straight-line monotony. Check out ZGallerie's white horse bust; it's a great way to introduce sculpture-like art on a wall at a low price point. If you have an extra $12K sitting underneath your sofa cushions, go all out and spend it on a 9 foot cast iron horse.