To all the devs out there: what is the most elegant/interesting code snippet you have come across?

сука.
Makes the other person angry.

.#define if while
.#define TRUE FALSE

Makes the other person angry.

Anything in Whitespace, like the common Hello World http://compsoc.dur.ac.uk/whitespace/hworld.ws
Whitespace is an old april joke, but is supposed to work. It's a language made only with whitespace characters (space, tab, etc.). See the source code of the link above :-)
Next time I'll talk about RFC 2549, the famous extension of RFC 1149