Eternal Sunshine
Saw Eternal Sunshine of the Spotless Mind a few weeks ago. Quite good and thoughtful. As zany as the plotting is, you really don't have to worry about it. Though you spend lots of energy trying to figure out if a scene is present time, past memory, or some combination thereof, each scene carries through the single emotional thread of the love story.
All around good stuff with even the little details becoming important by the end.