Proper mountain biking shoes. Mainly because now that I appear to have been slung into an off-road group (eep!!), my completely flat road cycling shoes only seem to get me down to the bottom of a slope faster than my bike if it and I ever part company...
They're very cool. Literally. There's mesh above the toes so y'get a nice breeze coming through.
...and therefore, wet feet when it rains...
The early bird might get the worm, but the second mouse gets the cheese.