Fighters who were way above their competition.

I don't particularly care for dude, but recently Floyd Mayweather comes to mind, especially in this era..

 

In the past 5 years, Wladimir Klitschko has been undisputedly much better than anyone he's faced.

So have Floyd and Pacquiao but as they didn't face off we don't know who is truly dominant.

 

For most of his career, Jimmy Wilde was head and shoulders above fighters his size, and only came into difficulty against significantly larger foes.

 

It's a misconception. If you start reading New York Clipper, for example, there was a lot of boxing activity in the USA, a lot of fights, exhibitions on regular basis in larger cities, etc. I can't say when exactly it started like this, but a lot was going on in 1860s-70s.

 

Whitaker... Jones... Ali... Greb... Johnson

 

Can't really say that Salvador was way above Eusebio Pedroza.