Tonight has a theme: family lives disrupted by a man's dark past catching up with him. Caché spends much more time developing characters, though. In fact, that's almost all it does, and it does it interestingly: unlike a Hollywood film, Haneke doesn't seem to care much whether or not you like his protagonist. I found that refreshing.
Man, that scene, though? I have a notably different reaction on second watching, but it's still a serious kick in the gut.