| Define unique.... Well here goes what I consider to be in that category from what I have.
EHX POG2: this thing can make organ,cello,flute,chorus,8-string bass, mellotron flutes, synth pad-like sounds, slow-gear, excellent octaver with a LPF and Q to make it sound however you want and sooo much more.
Montreal Assembly- Wrong Side Of Uranus: it's a bitcrusher in which you can select between 1-8 bits, dirty tremolo, angry fuzz, and weird dirty synth like sounds (robots vs. aliens). Check my review out (search for it in the effects forum).
EHX Memory Man with Hazarai: it's a digital delay with up to 3 seconds, 30 sec looper. Has a low and high pas filter for repeats, modulated delay which can sound VERY analog, but if set right can make flanger, chorus, reverb and even this cool whammy dive bomb like effect.
A few of my other pedals can make unique sounds bt usually require 2-5 to work in tandem. | 
