Some examples of Expressionist paintings on this little page, if your're interested.. (check out the quotes in the bottom of the page..;-). Max Beckmann (lot of great paintings, love the colors), George Grosz ("to Oskar Panizza" is fab), Otto Dix (not for the self portrait..) & George Rogault ("Slaughter") are some of my personal favourites on this field..
www.artlex.com/ArtLex/e/Expressionism.html