All of these pieces I love are by famous artists, but they're some of the less celebrated works - and that's part of why I like them.
For example, Van Gogh's best known piece is probably Starry Night. But I like The Cafe better, for many reasons. It gives me the feeling of being peacefully alone in a public place. In high school, I often went to Perkins late at night for a cup of tea and a muffin, and I would sit in a corner and write till the place closed. This painting brings that feeling to mind - there's some minor bustle around you, the night is gently magic, and you're content to watch the world rush by in all its glory.
I also love the solitude in this piece by Salvador Dali.
Better known as That Mustachioed Guy Who Melted Clocks, Dali didn't need bright colors all the time to make a strong statement. Follow the link above for some interpretations of his work if you like. Personally, I love the idea of the flower-head: the rest of her body is solid and grounded, but her head is elsewhere, lighter, maybe even dreaming. I feel a sense of... dark whimsy, I guess. Note the girl with the hula hoop in the background.
This is my favorite of Picasso's Blue Period. There's a lot of sadness here - the woman with her back turned, hugging her knees - but there's comfort, too. I love finding the different colors Picasso included here: blue and black, yes, but also brown, yellow, and purple. It's a reminder that there's always more than first meets the eye.
It takes more than good words to inspire writing. It also takes beauty in every form.