I bought an Ibanez OD850 a few months ago, there's a review of it in the reviews section of the forum. It's a great fuzz pedal and it works well with humbuckers, originally I was looking to buy a fuzz face but I tried out three versions and they all worked better with single coils than humbuckers.

The big muff is a solid option too, sounds great, personally I prefer the bass muff pedal on guitar, another favourite of the ones I've tried was the Death by Audio Fuzz War pedal.

One thing I have discovered is one fuzz pedal is never enough.