The one that started it all, the Digitech Whammy WH-1's two-octave up/down Whammy option, detune section and Harmony octave capability made it an instant classic amongst experimental guitarists. Used by the likes of Tom Morello, Jack White and Joe Satriani for the pedal's responsive shifting power, the WH-1 is a holy grail pedal of the '90s and a crown jewel in any collection.
As far as whammy pedals go, the Digitech Whammy WH-1 Original is probably the best sounding one as the tone quality is outstanding. The tracking is also great and I find it easy to control the pedal and get the sounds that I am looking to get. I probably like using the single octave up the best as I find using two octaves up is kind of ear piercing and I usually don't have any use for the other intervals, although I can see why they would be cool to use as well. Even though the other whammy pedals sound pretty great as well, it just seems as if they got it right on the first try and the WH-1 Original is the best.