I found this to be pretty accurate history of the SLR -> Early History of Single Lens Reflex (SLR) camera

Keep in mind that arguably the single most important development in 35mm SLRs was Asahi Pentax instant return mirror. Prior to this the viewfinders would blackout until next frame advance or some time until the mirror would drop after firing. If you go by the December issues of photo magazines in 50's on up you will notice the that SLR model releases - and presumably sales, started to exceed exceeded rangefinders after this innovation.

There is no denying the Nikon F's roll - as well as Nikon's dominance in that period. You only have to look at the short life of Canon's Canoflex - released the same year as the Nikon F to know this. I am sure that Nikon's quality and marketing strength in the rangefinder business greatly helped. And it took them >10 years to correct all it's shortcomings with the much anticipated release of the F2 . . .

I seems to me that Topcon is probably the most underrated during the early SLR period.