a) Superman is the last survivor of the planet Krypton. As is woefully unprepared homeland is subjected to a prodigiousand catastrophic explosion, he is sent by his loving parents to Earth on a spaceship. He comes here and basically grows up on a farm until he realizes hes better than that. Than he moves to the city and proceeds to beat the shit out of everybody.
b) Anybody who performs such a tremendous feat as to be declared a "superman"
a) I would bet millions of dollars that pre-crisis superman could destroy any character in the comic universe, DC or otherwise. He was wickedly strong and foolishly overpowered. Those writers were smoking crack.
b) Magic Johnson is superman. There have only been a few people in the world to get AIDS and not die; but Magic does it in style.
Magic Johnson > AIDS
Magic Johnson style > Big Ron Style*
Magic Johnson = Superman
*Big Ron Style being developed by Ish for the West Coast Customs client "Ron" on the ever-popular mtv program "Pimp My Ride"