I have two favorites. One is definitely the ZVex Wah Probe. It is also my favorite of the Probe series. It's neat, because you can tweak it more than most basic wahs. My other favorite is the Maestro Boomerang Wah. It is great for getting scratchy filtered 70s Krautrock sounds. If you want the sound of Neu, this is it! The only problems: It is highly susceptible to RF interference. All you will hear is local radio. It is likely nowhere near true bypass or noiseless, but, who cares. It's awesome.