An EL Nikkormat that I purchased new at the beginning of the 1970's. Its aperture priority exposure automation was a big improvement over my 1965 Nikon FTn with its match needle metering (also purchased new, a gift from my dad that still works great, as does the EL Nikkormat). The EL Nikkormat was my preferred SLR for many decades until my Nikon D700 purchased new in 2008, as I never found fighting with autofocus about what to focus on to be much of an improvement over manual focus. So in 50 years, the only innovations that prompted purchase of a new camera were the SLR, aperture priority exposure automation, the instant feedback of digital, and perhaps, in the near future, an electronic viewfinder with magnification to make manual focus easier. Of course, I now have lots of other 35mm and 120 film cameras just for fun, all purchased used, mostly at ridiculously low prices, after people started dumping them.