We have a variety of gear, for different types or shoots... different purposes. 

This is a widely debated topic, that is - in my opinion - as varied as what type of refridgerator do you want. Ultimately, ONE THAT ALLOWS YOU TO DO THE JOB! 

The brand of the body matters little, other than some brands have a reputation for specific 'pros and cons' - certain abilities, and quarks. Ultimately, body wise, there are tons of brands, but the most common decent body brands are Canon, Nikon, Panasonic, Fuji, Olympus, and Sony. Nearly everything else is far behind, and meaningless, in most cases... of quality, options, or flexibility. (And few normal humans can afford the Hasselblad H5D-200c MS... which is the massive 200 megapixel medium format portrait king many of the fashion photogs use, for a variety of reasons. Seriously, they've had a 200 megapixel single image capture ability since 2006... if you have $45,000 laying around, for just the body, you too could have one... but they suck at sports action). 

Personally, I use Canon for still images... and Sony for video. My e-Mount Sony's have an adapter that allows me to use any of my Canon EF lenses, which is an added benefit; especially when teamed with the Metabones Speedboost (which is amazingly baffling at how it can actually PICK UP - GAIN - ADD - a stop of lighting). Over the years, those are the 'body' brands I have the most of, and use the most. 

However, the BRAND of the body is far less important than the QUALITY OF THE LENSES, and the options necessary for the type of photography you're planning to do. 

Glass - Lenses - regardless of brand... is rated based on:
          ~ speed - low number f/stop, which allows in more light in low light situations
          ~ durability - how tough is it, if bumped, dropped, or just used in rain or dust
          ~ mount type - which impacts which makes and models it can work on
                 (example: EF will work on all of the Canon dSLR's, but the EF-s
                   only works on the crop sensor cameras, NOT the 'FULL FRAME' bodies)
          ~ prime or zoom - fixed focal length, or adjustable zoom

Memory Card Options: 
          ~ SD cards are pretty standard these days, small, compact, high speed, and large compacity
          ~ Compact Flash, is the second most common... however, more fragile than the SD cards
          ~  Some cameras allow dual slots, and even different types. But the SD's made today are really tough to beat. 
          ~ Sony's proprietary stuff (I suggest stearing clear of, IF there are other options)
          ~  SSD (solid state drives) and P2's also occasionally crop up, but unless you have deep pockets stay clear. 

Full Frame vs Crop Sensor: 
         ~ Full Frame sensored bodies generally have a greater sharpness, faster drop off on DOF (Depth of Field), a greater enlargement ability, and a much higher entry level cost. 
         ~ Crop Sensors are like a built in multiplier, depending on the crop factor, which is usually 1.5x for Nikon and 1.6x for Canon dSLR's... which is useful if you're regularly shooting things at a large zoom factor, like birds or sporting events. 

         ~ Full Frames allow you to generally 'get closer' (distance wise) to the subject, without parts being 'cropped' out, off frame. 
         ~ Crop Sensors allow you to zoom further (for example, a 400mm Canon on a crop sensor is like 640mm on a full frame)

         ~ Full Frames were once considered the only 'professional' option, but that's not been the case in a few years.
         ~ Some companies, like Canon, developed high-end pro-sumer bodies that rivalled the power, speed, megapixels of the full frame bodies

Supports & Stabilizers: 
         ~ Monopods
         ~ Tripods
         ~ Gimbles
         ~ Jib Cranes
         ~ Remote Pan/Tilt
         ~ GigaPan

The most important things in photography are:

KNOWLEDGE of the 'Exposure Triangle' and ability to adjust the camera in FULL MANUAL SETTINGS. These two things are key, regardless of the brand, make or model, megapixels, focal length of the lens, or speed of glass. 

To be continued... 

            The basics have been pretty much the same, with the primary difference being between film and digital. The next largest difference is SENSOR SIZE (bigger sensors are generally better)...