When I first bought a 'serious' camera in my film SLR days, I bought a Pentax ME super. A decent camera I know, but what I really wanted was a Nikon. However, I couldn't afford it. These days I have four of them - D850, Z7, Df and a F6 film camera.
For me there are two 'real' camera companies, who while they make other things are basically optical companies. And they are Leica and Nikon. I've tried other brands but these are the ones I keep coming back to. Currently I have sold all my Leicas (for financial reasons) and have gone exclusively back to Nikon.
My Z7 is now out of date, with the arrival of the II and I believe that Nikon have finally stopped making the F6 film camera. However, I'm intending to hang on to what I have for a while.
To be honest I didn't intend to end up being a Nikon fanboy, it just seem to happen. There is the obvious advantage that all my cameras can share my lenses, though the F>Z adapter on the Z7 can be a bit picky with some older lenses. I have a 24mm f/2.8D that I bought to use with my F6 primarily, however it won't AF on the Z7 + adapter, however it does on both the D850 and Df. An attempt to get us all to buy the new Z lenses I guess. But then they, like a lot of mirrorless gear, are overpriced. I'm still loving the Df and I bought a few cheap silver lenses to match up with it. For no obvious reason I have both a 28-80mm AND a 28-100mm zoom.
The last two lenses have an interesting history, some people (most notably the ultimate Nikon fanboy Ken Rockwell) have got it into their heads that the 28-80mm is a wonderful underrated lens and the 28-100mm is rubbish. I've even seen the latter described as the worst lens Nikon have ever made!!! This is of course total BS. The 28-80mm and 28-100mm lenses I have are virtually indistinguishable from each other. Both are sharp across the frame and perform really well on all my cameras (though they won't AF on the Z7 Plus adapter either) They are good value cheap, light kit lenses with plastic mounts that take great pictures. You can pick up near mint copies on ebay for around £50.
So my Nikon collection is building up, most of it bought S/H. And I have to say the used market is becoming a great way to buy gear gear at reasonable prices. The obvious cause of this is Covid-19. With job losses and even long term unemployment on the horizon, buying new is not an option for many photographers any more, particularly professionals. I'm pleased to report that my sales are moving in the right direction again, though not up to pre-quarantine levels. My hope is that I will be able to keep all four Nikon cameras and my Nikon lenses, though don't be surprised if you you read about some gear having to be dispatched to ebay.
Above 35mm f/1.8 and 55-200mm lenses on my D850.
The next part of this post is about a subject that has been discussed many times and my own particular take on it. Some Nikon 'full-frame' cameras, including both my D850 and Df allow the use of DX APS-C lenses on the full frame sensor with no automatic cropping, vignetting and all. The most well-known example is the 35mm f/1.8 DX lens which used wide open on an FX camera has virtually no vignetting. And another lens I use in this way is the 55-200mm II DX zoom. Now I've had some comments in the past questioning why on earth I do this. And this is why.
Nikons DX lenses are generally lighter and cheaper than their FF equivalents. But the problem is on FF you have to put up with that pretty nasty vignetting in most cases. Not surprising since these lenses were not designed to cover a FF sensor. You can use the lenses with a DX crop but you lose a lot of sensor real estate doing this. However there is a way round it.
