"Transparent Overdrive" has been a buzzword for a while. For our taste, this is THE one : The Greer Lightspeed adds gain and grit, but leaves your guitar and amp's character 100% intact. A Guitar Bar favorite!
Greer's Tone Smuggler is a unique pedal : at lower settings it's a very transparent overdrive pedal with a GREAT tone knob, at higher gain settings it morphs into an almost-fuzz pedal. Loud and proud, and very adaptable to your personal rig.