It occurred to me the other day that while both of my main user cameras were SLRs and could take a variety of lenses, I only use one lens most of the time. For the Nikon N80, I have a Nikkor 24mm, 50mm, and 70-210mm. For the OM1, I have a Zuiko 50mm and Vivitar Ser1 70-210mm. My "go to" lens for both cameras is their respective 50mm lenses. For both cameras, I think I would be just as well served by a 35mm or 40mm lens, but I went with the 50mm because they're usually faster (f1.8 vs 2 or 2.8).
I started thinking about this when I found myself looking at the Voigtlander Bessa R3M while thinking how nice it would be to have access to all those Leica, CV, and FSU lenses. My next thought was that I'd probably end up with whatever lens I bought at the same time as the body and maybe one other, if that. It was brought up again when I read Mike Johnston's article in this month's B&W Photography.
Do any of you find yourself only using or owning a single lens for your interchangeable lens cameras?