Star Wars Galaxies has one of the best, if not the best, selection of art to decorate your houses with of any MMORPG!
This gallery shows all the paintings and posters, lists if they are obsolete or not, and provides information on where they originally came from.
Obsolete means the painting is no longer obtainable in game as loot or a quest reward, can not be crafted anymore, or was a one time gift or reward. If you want one, you will have to buy or trade for it.
Crafted paintings are listed by their default name.
Descriptions of the different types of paintings can be found here.