Leica M2 with a Summicron 35mm lens; used only this for nearly twenty years.
About twelve years ago, I picked up 2 M4-P bodies, and a 50mm Summicron and a 28mm Elmarit lens. This way, I never had to remove lenses and could quickly provision as I traveled extensively.
Finally, about five years ago I picked up a mint condition M8.2 because I needed the digital workflow for a while.
Of these, I could easily go back to the M2 with a pre-ASPH 35mm Summicron lens without giving it a second thought.