I'm waiting to get my Solarus back to try it, but I recently traded for a Nick Greer Gold Nugget, which I LOVE with my Mesa/Boogie Studio 22 (it actually makes that amp sound a lot like the Solarus does when it's up around
. Not a fuzz, but a great pedal, and it works REALLY well in series after a fuzz.
I've got a Guyatone TZ1 that I use for bass. It sounds really shrill with guitar through most amps, but the Solarus actually makes it sound pretty good. It's not a conventional fuzz - I guess it puts out more of a sawtooth wave than a square wave, which implies that it's not based on simple clipping. I love the sound of it, but it does tend to get lost in the mix.
Russian Big Muff is a no-brainer. The LED broke on mine, and I finally got around to replacing it with a yellow (or was it green?) one recently.
I actually really like the distortion in the EH Bass Balls, but I don't really like envelope controlled filters, so I never use it. When I know more about electronics I'll probably try to replace the envelope follower with an expression pedal control and have an EH Talking Pedal clone.
Built one of those Ultrafuzz things fron the Electronic ProjectsFor Musicians book. It's hideous, but in a good way. I doubt I'll ever use it with a band, but I've been doing some solo music that uses Commodore 64 and a few other vintage computers, and the Ultrafuzz would probably sound right at home with that. Very synthetic with ugly, glitchy gating.