I’ve tried a few, including the much celebrated OC5 but I’ve now found the absolute beast that is the Foxrox Octron. It is, to my humble ears, the best out there by a mile.
It has 2 flavours of octave down and a really musical octave up fuzzy side. To be honest I think it is basically an expertly executed analogue version of the OC3: an OC2 sound plus a dirt tone. Sounds epic and needs no tweaking.
I know I sound very gushing here but having bought and sold lot of pedals in the last few years I’ve become very picky, so it was such a treat to find this.