Gear matters much less than most like to believe, but for those who really need to know –
I have been shooting with Nikon gear for many years now. These cameras have never let me down and provided bulletproof performance even in difficult conditions. The current models of choice are a D4 and a D750 (both full frame cameras with excellent dynamic range, color rendition and low light performance), and of course a wide range of prime (fixed focal length) and zoom lenses. A number of GoPro cameras provide extraordinary perspectives in dangerous and/or impossible places.
For the ultimate quality in fine art projects and applications under highly controlled conditions I use my Hasselblad H4D-40 digital medium format camera, which provides unmatched image quality that is almost impossible to achieve with smaller sensor sizes.
As always, your mileage may vary — what works for me doesn’t necessarily mean it is the best tool for your job.