Soliciting opinions: What is your favorite (format/lens choice) combination when shooting on the street?

Although I shoot in a variety of formats, the particular choice of camera is usually - but not always - determined by the subject matter at hand. Such is, for me, most obvious in the case of street photography, where being inconspicuous, quick and quiet are paramount. Having shot on the street with 35mm SLRs (Nikon F2s, F3s and F5s) as well as TLRs (A couple of Rolliflexes) over the years, I eventually settled on the 35mm rangefinder (loaded with HP5/Tri-X) as my preferred format for this type of shooting. A big fan of Jay Maisel (one of the primary reasons I first picked up a camera as well as the reason I was a long-time Kodachrome shooter), I am a committed adherent to Maisel's Axiom #1 (i.e. "The more you carry, the less you shoot."): my street-shooting "kit" (a Leica M6 with a 50mm Summilux ASPH) is the epitome of simplicity. Using this camera/lens combo not only allows me to concentrate fully on what unfolds around me, it also, I think, forces me to work (see) harder and become more "engaged" with my subjects. Further, in my view, I do not miss shooting opportunities when changing lenses. What about others out there in APUG-land? What is/are your preferred tools for this type of shooting?