Shaquille O’Neal and Kobe Bryant
Technically, O’Neal and Bryant’s feud never really entered the public realm but everybody knew they hated each other. The pair played together for the Lakers as Bryant emerged as one of basketball’s top players. This threatened Shaq’s status as the game’s top player and ignited a fierce rivalry (via The Mirror).
They had spats in public where they blamed each other in front of the reporters. It threatened to blow up into something incredible but it never did. These two men were fierce competitors with massive egos and that’s why this was so big. Later their rivalry cooled and O’Neal cried after Bryant’s tragic passing.