Pharaohe Monch - "Simon Says"
It almost feels redundant including Pharaoh Monche's classic in this list—it is the ultimate in pulse-raising, lip-curling magnificence, and if you don't know that you've been under a soundproof rock for the last two decades. "Simon Says" is the song that inspires lists like these, and you know it from the opening notes: massive horns give way to Monche's rallying cry to "get tha fack ahp!"
It's nasty, grimy, unapologetic rap that could raise the dead. If this doesn't put a sneer on your face, seek help.