first of all... what kind of photography are you interested in?
second... dont buy zooms. (this also depends upon the type of photography)
I wonder why the categorical condemnation of zooms? They are an order of magnitude better today than they were when I bought my first Nikkor zoom back in the 1970s. Today's premium zooms are fast and sharp. They are less distorted. And they are infinitely more convenient inasmuch as one does not need to swap lenses about so much.
three... canon and nikon are not the epitome of quality photography. especially in lenses. if you want to get the best of quality you might want to look into zeiss and leica etc... for example, if you want to buy 85mm, I would presume that you want to get into portraiture. then you should buy zeiss otus. but it will cost you as much as 24-70 and 70-200 combined.
Zeiss and Leitz do in fact make some of the very best glass out there. However, in my opinion and experience, having a Leitz Summicron or a Zeiss Planar is no recipe for success. The difference in quality between premium glass across the major brands is minuscule. Top end Canon and Nikon lenses are plenty good enough, and in my opinion they have been good enough for a very long time.
I'll share an example to make a point. Consider the classic "normal" lens. I have three:
1: a 1967 Nikkor 50mm F2 which I use on Nikons F, F2, and D700. (about $40 on the used market)
2: a 1954 Summicron 50mm F2 on a Leica M3, (about $300 on the used market), and
3: a 1969 50mm F2 Kiev Jupiter 8M (Ukrainian Carl Zeiss Sonnar copy) (about $15 on the used market), fitted to a Kiev 4a (Ukrainian Contax II copy).
The Summicron is ever so slightly sharper wide open. The Jupiter and Nikkor are about the same as each other, having a bit more contrast than the Summicron. One looking at a print made of the same subject from each of these three lenses would probably not be able to discern any difference between them. Certainly not because of sharpness. Maybe the most discerning amateur photographer could see some differences in bokeh.
Point is, shouldn't we get the concept clear first? Perhaps we should not worry so much about the ability of today's premium grade glass to deliver sharp, high quality images. Most of the bad images we make nowadays will be because of fuzzy concepts and bad techniques, not because of ineptitude of lenses.
btw, I hate canon and nikon. and if you buy sony (like me) you can almost use any lens. be it canon or nikon or leica or minolta.
Why the categorical hate of the top two camera makers in the world? FWIW, Canon, with its short flange-to sensor distance, will mount more other-brand glass by accident than most other cameras can on purpose. And there is so much F mount glass out there that there will never be any shortage of lenses for Nikons. And what about Pentax? A great brand. Poorly marketed maybe, but very good. Pentax will mount hundreds of lenses from Pentax, Yashica, Mamiya, Ricoh, Zeiss, and dozens of other brands via its bayonet+M42 capability. Nothing wrong with Sony either. They are leading the way with Zeiss branded glass and improved electronic viewfinder technology.
Most of our problems with photography cannot be solved by switching about between brands and lenses. Perhaps we should invest in improving our skills instead. A talented imagemaker will consistently make better pictures with any camera. One who does not understand photography will make poor pictures with whatever equipment he buys. This is one fact that time and experience will show each of us sooner or later. Cameras don't make pictures. Photographers do that.
