Fuzz is pretty much the most alien sound that you can get from your guitar. "Overdrive" and "Distortion" effects still contain some vestige of the original guitar sound (if they're any good!), but fuzz mutates your guitar sound completely. Fuzz is generally over-complicated by the boutique clowns. The Fuzz Face is just a wrongly constructed microphone preamplifier circuit with too much gain, so that the amplified signal "hits the rail" and takes the transistors out of their linear comfort zone! It's great fun to experiment with Fuzz circuits. You can really annoy your family and neighbours with the raucous racket coming from your workshop / practice room / garage or basement! My favourite Fuzz is one of my own devising. It's largely based on a Macari's (Solasound) 1970s silicon Tonebender. A friend of mine had this Macari's effort in a big case, and it sounded dreadful. It was probably a "Friday Afternoon" job (after the lunchtime in the pub) because it had several obviously wrong component values, and he asked me if I could make it "sound right". An hour later, I'd not only corrected his Tonebender into something better than just useable, I'd also jotted down and begun to modify the original circuit. I changed the tone control into something much more useable, changed the two-transistor "fuzz engine" part of the circuit for a better range of effects, modified the input preamplifier to give a little bit of useful tone shaping, and modified the output stage for a bit more gain to kick the input of my AC30 a bit harder (if I wanted to). I built a couple of these, to see that the circuit was reproducible, and boxed them up in small diecast boxes with PP3 batteries inside them. I used low noise transistors (BC109C in one of them and ZTX384W in the other) so they didn't hiss. They still sound phenomenal more than 35 years later! Over the years I've built hundreds of them. I've incorporated a few little improvements like relay bypass to minimise the risk of clicks and pops due to wearing footswitches, and LED indication of operation (though it's pretty clear when the effect is engaged!). I also made a "super high gain" version of the circuit that has seen service with some serious shredders. The latest variant has a mode switch for normal / high gain. There's also a version with internal controls only, so that all that's on the outside of the case is the footswitch and the jacks - some players like the "set and forget" simplicity of that approach (Gilmour used to snip the knobs and spindles off the pots on his Tonebenders to prevent anyone twiddling the settings away from the magic spot!). In answer to the original question about which is the "best" Fuzz..... It's the one that you get on with! It's the one that gives you the sounds that you want. It can be as simple as a Fuzz Face with two controls and less than fifteen parts, or as complicated as a Fender Blender or a Univox Super Fuzz. The Vex "Fuzz Factory" is just a modified germanium Fuzz Face with a silicon preamp transistor and extra controls - some people think that's it's the canine's gonads, but it doesn't do much for me..... All you can do is try a few out until you find the one that you like. One word of warning though - it's easy to become addicted to the various varieties of Fuzz device - each of them has their own quirks, unique sounds and "feel". I know some folks who've become completely obsessed with getting different Fuzz Boxes - one pro player i know has six or seven on his pedalboard at any time!