Don't miss the BBC poll on what is the world's most beautiful equation. Are you a fan of Einstein's field equation, or does the Riemann zeta-function hold you in raptures? There's some great commentary on the twelve candidates here.
How did I vote? Well, that would be telling, but the fact that my very first publication is titled Auxiliary-field quantum Monte Carlo calculations for the relativistic electron gas [read it here! – at least if you have access to the Journal of Physics: Condensed Matter] might give the physicist readers a few clues.