Canon EOS 5D Mark IV is one of the most celebrated Full-Frame DSLRs in the market. It has a 30.4 megapixels CMOS sensor & uses Canon’s DIGIC 6+ processor for image processing. It offers an astonishing ISO range 100-32000 (expands to 50-102400), which will help you take pictures in very low light. It can shoot at a 7 fps in full resolution. It can shoot videos in 4K at 30 fps & full HD recording at 60 fps. Its body is made from magnesium alloy to withstand tough working conditions. It supports WiFi, NFC & USB 3.0 for connectivity and has built-in GPS unlike most of other Canon models. It is priced at US $3299.00 (body only).
Also check out other models of Canon series, such as Canon EOS 7D Mark II, Canon EOS 800D & EOS 80D.
Nikon D850 is one of the very few full-frame DSLRs to have a huge megapixel output. It has a 45.7 megapixel BSI-CMOS sensor & EXPEED 5 image processing engine. It can shoot at 9 fps in continuous mode. Its ISO range is 64-25600 (expands to 32-102400). It has 151 autofocus points for accurate focusing. It has a 3.2” LCD display, which is tilting and touch screen enabled too. Viewfinder is optical pentaprism type. It supports WiFi, Bluetooth & has NFC support along with inbuilt GPS. It costs about US $3,299 (body only).
Also check out other models of Nikon: Nikon D500, Nikon D7500, Nikon D5500
This is a 42 megapixels full frame body from Sony with its BIONZ X processor. Sony is famous for its Translucent Mirror Technology; it allows the image to be seen while being clicked at 12 fps. Sony uses electronic viewfinder for that. Like other cameras on the list, this supports NFC & WiFi too. It has 399 focus points, which is the highest in this category of cameras. It is available at around $3199.
Also check out other model of Sony: Sony Alpha A9