Gnomeratron VTF (Manufactured by talkbass member McSpunkle, who is a great guy, and a pleasure to do business with.)
This thing can do it all. It is my favorite fuzz. And it will give you that huge, distorted, heavy sound you want. It also has an absurd amount of knobs and switches that will let you dial in pretty much any fuzz tone you can imagine. It'd be my "desert island" fuzz. Do yourself a favor and check it out.
A close second would be the Iron Ether Oxide. Others have mentioned it because it is an excellent pedal.
I also own a Malekko Assmaster, a Boss FZ-2, a ZVex Machine (technically not a fuzz, but close enough), and the fuzz section from a Chunk System Brown Dog. The VTF and Oxide are the best I've owned, but I keep the others because they are useful in certain situations and I have three pedal boards to fill.