I would see something like Requiem for a Dream more than two times, first for the disturbing story, then the cinematography and the techniques...there's always something new that I see in this film every time I watch it.  

I watch David Lynch's movies twice, esp. that new one, Mulholland Drive.  Until now, I'm not sure, if it's a masterpiece, or Lynch is fucking with my mind or both...

I always watch Wong Kar-wai's films twice, more than twice.  Like Requiem, there's a wealth of film school tips and techniques, in every shot/sequence, the composition, angles, the editing--everything.  Plus, his characters are so complex, you need more than one viewing to figure them out.  