Tube Screamer Mini : You Know What it is Already

I use it mainly for a mildly overdriven clean/on-edge/bluesy tone. It does that very nicely, and has pleasing harmonics & touch sensitivity.

I also use it to add more gain, tightness and a mid-range, "vowel-like" character to my high gain rhythm tone. It does that well too, which is why that's a classic use of it. That works well stacking into another pedal or running into the front end of an amp.

I had to have one, and I like that it mimics the 808 design in micro. It's an aesthetically pleasing and sturdy, weighty little box.

My only complaint is that you can barely see where the smaller tone and volume knobs are pointing, especially from any distance or with the led on. Some little white strips there would help with visibility. Take a leaf out of the Nobels Odr-Mini book, they have off-white/glow-in-the-dark ones.