IconStore - Free icon packs by first-class designers
MonoLisa - font follows function
Icon Shop - Get beautiful premium quality vector icons
Mononoki Typeface - Font for programming and code review
IconBros - Free and continuously growing high quality icons
Android Icons - Androidicons is a professional, handcrafted icon set with 250 icons in 14 different colors and 5 sizes, including an icon font and all sources.