I think the "best" bosses would be those that grew the business, mostly managed to avoid jail, kept the peace and died of natural causes.

So in addition to those you mentioned (Accardo/Gambino/Trafficante Jr)I would include Tommy Lucchese, Carlos Marcello, Frank Costello, Luciano, and Joe Zerelli.

The worst bosses would be people like Sam Giancana, John Gotti, Nicky Scarfo, and Amuso/Casso-people that didn't know how to build business, liked killing too much or couldn't keep a low profile.

"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming

Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.