I've still to find the filter for me! I'm currently using an early coloured/etched 3 Leaf wonderlove,I love it mixed with fuzz and octave, (especially when they are in its loop) but struggling to find a tone I like on its own, it's just not squelchy enough. My favourite was the original big box Qtron I owned! Buts it's massive a PITA to power and sucks tone bypassed! I've had the EBS IQ, digitech BSW, Tone factor bottom Feeder, Bass balls and various multi fx and haven't found "the one" yet.
tones I love are "back to love" Brand new heavies, "fell n love with a boy" Joss Stone ( guy used a Moog Murf I believe) and anything by Bootsy:) got my eye on the Emma Discombobulator at the mo!