Blair Wind
The Iron Avenger
Superman -
Probably the most rounded character of all. He has the physical stats, the speed, and the energy expenditure to compete with just about everyone.
Weakness:
He lacks the exotic energy manipulation feats that the others on my list have. I don't count his "psychic martial art".
Thor -
Biggest combination of physical stats and exotic magical manipulation. He can take a beating, give a beating, or use magic to skip the entire fight.
Weakness:
For all his abilities, he lacks the speed to counter or be extremely useful against all opponents.
Silver Surfer -
He is the guy with the most exotic abilities of all - he can basically manipulate the Power Cosmic to do anything he wants.
Weakness:
He's a better long range fighter than a top tier brute, physical stats being his one weak point.
Wildcard:
Green Lantern -
Take your pick of which one, but they do wield the most powerful weapon in the universe. If it's a Green Lantern title, they crap on every single Earth based hero, including Superman. If it's a JLA title, depends on the writer, but they are the most versatile gun they have. I've always been a fan of theirs, so my opinion may be biased, but I feel that the physical representation of their willpower gives them the exotic abilities akin to Surfer and upgrades their physical/speed stats to Superman level.
Weakness:
Entire ability is based on energy. That has been exploited in the past.