DC and Marvel`s top 10 heaviest hitters respectively(in no particular order).
(Space)Superman (pre 52) vs Hyperion(current)
(Earth)Shazam(Captain Marvel pre 52) vs Thor
(Space)Dr. Manhattan vs Silver Surfer
(Earth)Orion (pre 52 enraged) vs Hulk(enraged)
(Space)Mr Majestic(pre 52) vs Gladiator(at max confidence)
(Space)Martian Manhunter(pre 52) vs Beta Ray Bill
(Space)Captain Atom(Pre 52) vs Black Bolt
(Earth)Apollo(pre 52) vs Wonder Man
(Earth)Flash(Barry Allen) vs Juggernaut(classic)
(Earth) Wonder Woman(pre 52) vs Hercules(classic)
Half the battles take place in space the other half in abandoned cities on earth.
No BFR(for the combatants on Earth).
blitzing is allowed.
win by KO or Submission and even Death.
In each battle the combatants start roughly 50 feet apart (on Earth and in Space).