The Legendary Big Muff.
The Electro-Harmonix Big Muff Pi is with no doubt one of the most iconic guitar pedals on the planet. You probably hear it on records all the time without even knowing it. There are a lot of different Big Muff versions which went in and out of production over the years and this Electro-Harmonix Big Muff Pi is the current standard, has been for a long long time now. The Big Muff is famous for its violin-like sustain, creamy tone and simplicity vs versatility great ratio.
It is also priced well, so no need to save up for months until you get yours. Size-wise, it is big! If you lack space on your board check out the Nano and Little Big Muff Pi versions. They sound similar to the Big Muff Pi and come in smaller housings.