For those of us, like me, who hate (a) the tone suck that most wah pedals introduce to the signal chain and (b) trying to turn the thing off or on mid-song, the G-Lab TBWP Wah pad is essential.
Solidly built, clear instructions (including info on how to mount it to a pedalboard, etc, the thing just works. Silent and instantaneous switching, and true bypass make for a perfect combination.