aside from joe louis who is the most skilled HW ever?

This: JAMES TONEY

 

People have interesting interpretations of "natural heavyweight". And by interesting, I mean stupid.

 

Big men - wlad
overall-Holmes, Charles(did anyone mentioned him?), Tunney(WAAAAY ahead of his time), Greb(cross arm defense©), Walcot.
I should also mention Tyson because he truly was an innovator(or it was Cass, but who cares?).

 

Some of these may be argued to be a little outed due to their time and rule changes but some not mentioned too much so far who might be a chance would include:

Corbett - In his time, he was probably the highest regarded, skill wise.
Jackson - If Corbett wasnt, Jackson was.
Fitzsimmons - Different type of skill, mixed with unorthodoxy and power, but you had to be skilfull to do what he did.
Tunney - The Dempsey masterclass probably has him as the favourite, provided you can get over the fact that he was really a light heavyweight.
Max Schmelling - Extremely Skilful.
Billy Conn - Based on the Joe Louis fight, he has to be a very good chance.
Rocky Marciano - This will be wildly laughed at, but this guy fights a basic style but is perfectly skilled. He keeps his arms up always to defend himself. He puts his full body weight behind every punch and he never loses sights of the basics. He crouches low and ducks well. He isnt showy, just skilled. Does all the fundamentals properly, and not much more. It is no coincidence that what on the face sees a non gifted athlete never defeated in a professional fight. Always in perfect shape (which is a major skill in itself). For mine, i lean towards this controversial pick.

There are of course countless others who have good claims.