Which is the best / most suited / essential equipment for Macro Photography

Let me start of by going to the definition of Macro Photography :
Photography where the image formed on the sensor is equal / more than the size of the subject.

So how do we achieve this ?
A Camera & Lens combination giving a magnification of at least 1x or more.

The camera is straight forward, you can use almost any new modern camera.

But we need to be careful when we are selecting our lenses.
There are specialised "Macro lenses" where the optics produce very very sharp images (if you use it for say portraits you will almost always require softening in post production)

Macro lenses also 
Allow for close focussing (a few 10's of centimeters)
Usually prime lenses in the range between 50 to 200mm (I do own a Sigma 70-300 with a macro function between 200 - 300 mm which allows me to focus very very close ... those exceptions do exist)

One can also use extension tubes / Macro filters (additional lens in front of your regular lens ... I don't tend to like any piece of glass that is screwed on / like a filter due to a slight degradation in quality
Extension tubes also result in some lost functionality (cheap ones), and reduction in your effective aperture size available

Something to help you shoot low (a mat or tripod that allows you to show low & a head which allows movement in all directions ... as you will be shooting in many directions