I use 3 distortion pedals at once, or rarther 2 distortion pedals and a fuzz, plus an overdive after.
So to be specific my basic "clean" tone is actually overdriven by a Tech 21 Oxford, preamp pedal, that I have blended with dry signal, at an about 2:1 drive/dry ratio, this goes after my high gain distortion setup, which consist of an EHX Tri Parallel Mixer, with a Mosky Black Rat (RAT clone, in Turbo RAT mode) in channel/loop 1, a Boss MT-2 Metal Zone in channel/loop 2, and a Behringer FZ300 Superfuzz in channel/loop 3, all blended parallely in about equal measures with dry signal.
This gives me a monsterouly ballsy and heavy distortion, that however still retains a surprisingly amount of attack and definition, thanks to the dry blend, which does sound like it sits on top of the distortion, but blends in perfectly, thanks to the fact that is is overdriven.
A case of the sum being greater than the individual parts, and gives me the oppotunity to switch between combinations of drive tones.
Sounds glorious!
Parallel drives is where it is at!