I am no artist. Very unfortunate that I didnt get that gene, but my sister did. She's a great artist. So unlike her, I have to buy my own art for my house and make it look nice, instead of just being able to design what I want to have on the walls.
There are certain websites that I have found some great pieces at that you should take a look at if you are as untalented art wise (or very artistic and have no time to be artistic!) as I am, to find some nice paintings to put on your wall, I found a really great selection of artwork at www.cheapoilpainting.com .
Oil paintings are great for everywhere in your house. They have paintings like the Mona Lisa, Vincent Van Gogh paintings and many more. There are also Oil Painting Reproductions that are very nice and not too expensive to pick from as well.
Another nice option is for Oil Painting on Canvas, they have great pictures to choose from. It's always hard to find nice paintings that aren't terribly expensive and not great quality but these are great sites to look at.