Doomsday and Apocalypse
This isn't really a versus idea, more of a what if? Suppose that the Marvel villain Apocalypse, devoting his entire life to the principle of survival of the fittest, were to encounter the DC monster Doomsday, a being that was artificially evolved and engineered with that same goal in mind. What would happen? Would Apocalypse bow and acknowledge Doomsday as Master or choose to try and use Doomsday as his new Horseman of Death?