DarK is part of the DarK-theme-Suite, however it can be used as a seperate icon theme.
* Made to work on all desktop environments and widget toolkits
* All icons are based on 16px icons and were upscaled to get the same icon at every size
* Pixel perfect(no blurry icons)
* Optimized PNG's for best performance
* Probably one of (if not) the most complete icon theme
* Mono color and Recolorable to fit every theme
* Easy install (at least if you use a debian based distribution)