Post some suggestions for double features. Here are a couple of mine:

Collateral and Taxi (the two new films, this is what got me thinking about the subject in the first place -- I think it's funny that these two films are coming out about the same time, and would like to see them as a double-feature)

Run Lola Run and Go (I've said this one many times before, two different slants on sideways story-telling)

Kill Bill Vol. 1 and Kill Bill Vol. 2 (just kidding -- we're actually doing this tonight)

Who Framed Roger Rabbit? and Cool World (start off in ha-ha land, end up in la-la land)

Butterfly Effect and Mothman Prophecies (don't know why, they just seem like they would work well together)

Feel free to list, or feel free to justify your suggestions.