Electro Harmonix Little Big Muff Pi

This is the first distortion pedal I've used and I'm starting to love it more and more every time I try it. The distortion is pretty heavy and muddy and even on lowest settings it's very fuzzy and dirty. The distortion is excellent for heavy rhythm playing - it's very dirty but has a good attack to it. I find it a bit too heavy for lead playing, although it works with a bit of tweaking on the tone and sustain. Power chords roar with it and the metal housing feels like it can take beating. The controls can give you a few options in tone but one should keep in mind that even with sustain turned down it's still pretty muddy.

Pros:
built like a tank
brilliant for heavy rhythm playing/power chords
massive sound

Cons:
a bit too much for lead playing
doesn't "roll off" at lower settings/not very dynamically responsive (very muddy even when sustain and guitar volume are turned down)

This was the first single-effect pedal for my electric guitar I purchased 3 years ago, and it still is on my pedalboard, getting much use.
Let me first point out a downside - there is a clicking sound in the amp, when you use the footswitch. Otherwise, it is a fine little pedal. Its character is somewhere between fuzz and distortion, and this changes depending on the pickup you use (neck or bridge) and the position of the tone knob. The sound is very juicy and full, and the pedal is usable and great-sounding with all the different types of guitars, both humbuckers and single coils.The Little Big Muff would benefit from a separate low/high control, though.
The case is very solid, and surprisingly the pedal came with a battery inside, which is a pleasant bonus (you do not know that before you open the casing though).
A great purchase all in all, never had a single regret.