Hack? Probably kill aura.
But client wise I would say wurst, wolfram or jigsaw.
What's the best minecraft hack? XDXD
OptiFine 1.6.4 has to be the best hack out there to offer.
fullbright i think lol... idk
The best hack, is reach. I love it, KA is too blatant
I'd say killaura is pretty useful, along with aimbot with the bow.