I want to add a little spice to this discussion. I started thinking about the most collectible cameras- Leica, Contax, Zeiss, Exacta, Nikon, Mamiya, Alpa, Hasselblad, Rolleiflex, etc. Then I thought, which cameras (of major producers) are the least collectible, or say less collectible, and I came up with : Canon.
I would say Canon has been one of the MOST successful camera companies, and has produced some of the best cameras. But what makes a camera "collectible"? Collectable cameras are generally ones that had firsts (Leica, Contax, Nikon), were innovative (Ihagee, Zeiss Ikon), drove the market (Exacta, Nikon F), etc. They had something unique and special. Of course you can collect cameras just because you like them too. But Canon always seemed to be more of a follower. The Canon rangefinders are excellent cameras, and based themselves on Leica thread mount. The Canon SLRs were great and very popular, but did not lead the way, and did not really have a lot of amazing firsts. Canon digitals are a clear sales leader across all segments. But nothing in Canon is really out of the ordinary.