I have owned or own the following Nikon cameras:
Nikon F, plain prism
Nikon F photomic TN
Nikon F2, AS prism
Nikon F2, A prism
Nikon F3
Nikkormat FT2
Nikkormat EL
Nikon FE
Nikon FG
... and a lot of Nikkor lenses.
My favorite camera is the Canon New F-1. It is the best 35mm SLR i have used. I have two, including the coveted 1984 Olympics model. I sold a Nikon F3 to pay part of the price of the 1984 F-1.
The older Canon F-1, which I also own. is better built than the Nikon F2, Nikon F and of course the F3.
Now, many things have been spoken about Nikon being the "pro's choice". The answer is very simple and goes back to 1959.
In the late 1950s both Canon and Nikon were making rangefinders. But Nikon saw SLRs as the future. Canon had a good market share in rangefinder and rangefinder lenses. So when Nikon was about to introduce a SLR, Canon made a poor effort to say "me-too" and introduce a SLR geared to the amateurs. Canon, most likely, did not ever consider 35mm SLRs to be the pros choice, considering that their rangefinder already offered a complete line of lenses AND also reflex housing for lenses up to 1000mm.
So Nikon goes for a real pro SLR (Nikon F) and Canon brings out an amateur (yet well built) SLR, the Canonflex. The pros switch en masse to Nikon and the rest is history.
Canon then took their time to release, in 1971, a pro camera (F-1) that was a fully featured contender to Nikon. They also invested heavily in lens design, circa 1965, and I can safely say that in 1971 the whole Canon FL and FD lens line was more advanced than the equivalent Nikkor designs. But it was too late, the pros were with Nikon, changing systems is not an easy thing to do. Still, the F-1 was accepted as the "other" choice.
Now, who are Nikon? Are they really the best japanese manufacturers? Are they the "innovators"?
In retrospective, I think Pentax and Canon, through the 60s and 70s, were more innovative in optics than Nikon.
* Canon had most of the fastest japanese lenses through the 50s, 60s, 70s, and 80s. -- 50/0.95 lens, 24/1.4, 85/1.2, then the EF 50/1.0, et cetera.
* The 85mm Canon rangefinder lens of the 50s was so good that it is already a classic cult lens. The designers of those times (Hiroshi Ito, Jiro Mukai) are some of the most brilliant of the era. That 85mm design and the 100mm design were already more advanced than the contemporary Nikkors which were still using the old Sonnar configuration.
* Canon rangefinder lenses (leica thread mount) are still expensive stuff today... can't be bad or mediocre stuff.
* Canon brought out zooms using the 2-group design, the 35-70/2.8-3.5 lens of the early 70s was better than anything any other manufacturer had in that time, it took many years for Nikon to release a zoom lens using the 2-group design.
* Canon was the first manufacturer to find a way to do computer manufacture of aspheric lenses (back in 1970) so they released premium lenses with aspheric design that even Leica avoided to design due to the complexity of hand polishing aspherical surfaces.
* Canon in the mid 60s found out how to artificially grow fluorite crystals for low-dispersion telephoto lenses. Those FL-F telephotos were the best performing telephotos of the 60s and they still have very high performance.
* You can look at magazines of the late 60s and 70s to see how high was Canon FL and FD lenses' performance back in those years. Only after 1976 when Nikon released the AI lens line, did Nikon "update" their lens designs to the state of the art. For example I have a test of the 1965 Canon FL 19/3.5R lens and the performance was the highest of all the extreme wideangle lenses tested (including Nikon, Minolta, Pentax), only equalled by a Zeiss counterpart. The Canon FD 55/1.2 aspheric was most likely the highest performance normal lens of the seventies.
etc, etc.
Asahi Pentax was also a very innovative company in optics, an older optical company than Nikon and Canon. Only today people are finding out how good some of those Takumars were. Pentax in the late 50s and early 60s had a wider SLR lens choice than Nikon or Canon, and in those times they had some of the fastest SLR lenses as well. Their build quality is excellent, and they could have released the ultimate SLR of the 80s (Pentax LX), sadly it had reliability problems.
Minolta made and designed cameras so good that were used as the basis for many Leica R bodies. Minolta perhaps made the best camera bodies of all manufacturers!
Tomioka (Yashica) had a lens factory good enough to be hired by Zeiss to build Zeiss lenses...
Mamiya was also very innovative (see XTL camera) and is the real pro choice for japanese cameras in medium format, so they should perhaps have more prestige than Nikon.
Tokyo Kogaku (TOPCON) had amazingly high quality lenses in the 60s, some cult classics there. They had a 300/2.8 long before Canon or Nikon, for example.
Fuji Photo Optical (fujica) was the first manufacturer to have a computer for optical optimization (they built it themselves and it was the first japanese-made electronic computer), so they are heavyweights as well, at least in optical design.
All in all, Nikon is very much hyped in the forums. I say, research OTHER japanese brands as well.
Don't get me wrong, i love my Nikon F and F2 and my Nikon lenses. But i would never ever consider Canon to be an inferior brand in any way.