My readers know me as The Wildlife Ho-tographer using Canon equipment for 25 years. My camera/lens combo (if restricted to one) of choice is the EOS-1D X (waiting for the EOS-1D X Mark II to arrive) camera and EF 24-105mm f/4L IS lens for street / travel photography. For wildlife photography, it is either the EOS-7D Mk II or EOS-1D X DSLR and EF 200-400mm f/4L IS USM Extender 1.4x or EF 400mm f/4 DO IS II lens.
Fortunately, in most cases, I am not restricted to one camera and lens combo. You can see my equipment bag and works on MichaelDanielHo.com. In the world of wildlife photography, the three most important components, in my opinion, are in the following order : luck, skill and experience, quality of equipment. Luck can be enhanced by increasing the number of trips one goes on. In other types of photography, luck plays little or no part in the equation but the other two components still apply.
In the video below, fashion photographer Paul John Bayfield and DigitaRev went out on the streets of Hong Kong to see what an inexpensive camera can do in the hands of those who know the art of photography. If you are into street photography, one of the best is Fan Ho (no relation to me). Take a look at this post.