I have a large living room so there's a lot of stuff on my walls:
2 Antique Mirrors - one Empire, one Victorian on opposite ends of the living room. The victorian has two antique cake plates hanging on either side.
6 pictures, 4 of my kids and 1 of DB & SIL at their wedding and the last of DH as a child with his brother and sister.
A large painting of an abandoned farm that hangs over my mantel - which has lots of stuff on it.
Two prints
An abstract curio box with 4 lenox china animal figurines, an antique music box, our wedding cake topper (lladro), a mini-bicycle and som antique glass ware.
It sounds like a lot I know but my living room is 28 x 15.
I also have a 10 foot long window (argh try finding a curtain rod for that 
) and another window and three doorways.