Got mine. Now I really will have to see this film, no excuses...
I was tempted to go with this from the BBC4 tv film Surrealissimo: The Trial of Salvador Dali about Dali and the surrealist movement, starring Stephen Fry and Ewen Bremner, but weird as it is I wasn't sure it counted as a surreal film itself...
As usual, I'm in. This one's from Donnie Darko. Whether or not it's ultimately explainable, it's also very surreal, especially the first time you watch it and don't have a clue what's going on.