The Soda Meiser is a modern classic. I am generally uninterested in the lower gain settings on this pedal, but it does create a nice thick, aggressive muff-esque tone with more midrange.
I mainly use the pedal with the gain knob at 12 o clock and higher. The tone is still thick and aggressive, but more upper octave qualities reveal themselves the higher the gain is set. At the highest settings, the tone can be compared to a more extreme Ampeg Scrambler or a Fender Blender, with the scrambled upper octave accents and ring mod undertones.
The chaos switch is an awesome feature as well. It basically destroys your guitar tone, but makes one of the most chaotic and unique fuzz tones I've heard. It takes a lot of the bass out, so I like to run it through an octave pedal to add some bass into the tone. If you have ever heard of the term "velcro fuzz," the chaos mode is kind of like that, but also completely different in that it isn't gated at all and is capable of really long sustain. For lack of a better term, I would call it "carbonated fuzz," because that is what it sounds like: notes exploding into a burst of carbonation. Really interesting and beautiful note decay as well. The chaos mode is very fuzzy, but also clangy as well. Really interesting.