Joyo Taichi. Mild overdrive that gives "girth" and body to a thin sounding guitar. Especially nice for blues (demo at 5:34 min) :
Love my Taichi. It could well be my only OD pedal. You can drive it to almost fuzzland.
Another one I've had for a while is the Sweet Baby (Joyo again). A nice mild boost completely transparent to your tone.