It seems like we've watched so many hours of campaign coverage on TV, and seen so many pictures from the trail, that the faces of the four candidates are seared into our brain. At this point, if you ran into them on the subway, you'd do that mortifying thing where you see a minor celebrity out of the corner of your eye and you say hi to them as though they are a friend before you realize why you recognize them. (It's okay, David Cross is used to it.) Anyway, is it just us, or do they all seem to have perfected a special set of facial expressions?

Each candidate has four or five trademark looks that they give that says a specific thing, be it mock surprise, mock rage, real confusion, or real fervor. Sarah Palin and Barack Obama are much more expressive — McCain's age and limited range of movement limit him to just a few looks (angry, serious, freakishly chipper), and whatever Joe Biden did to his face limits his options (he pretty much oscillates between pensive seriousness and wild, white-toothed glee). So we've rounded up each of these familiar facial expressions and put them in a slideshow. Let us know if we're missing any.