Their first meeting was in Metropolis, when Batman was investigating a series of museum thefts. The two heroes, with
their vastly different styles and personas, were almost immediately at odds with one another. But they managed to put aside
their differences long enough to find the person responsible for the thefts.
Later, when Superman came into posession of a scrap book full of newspaper articles about his actions, he went to Batman to see if the Caped Crusader could deduce anything from it. Not surprisingly, Batman deduced that Superman and Clark Kent were one and the same! Superman had, of course, already determined that behind the mask of the Batman was Gotham City's playboy, Bruce Wayne.
Superman teamed up with Batman after Intergang stepped up its attempts to assassinate Clark Kent, Catherine Grant, and
Lois Lane. Together, the two were able to severly cripple that organization's infrastructure.
When Superman met up with Amanda McCoy, an ex-Lexcorp employee who had procured Luthor's kryptonite ring, he went to Batman for help in tracking it down. Batman had already obtained the ring, which had made its way to Gotham City following Amanda's murder. Upon realizing this, Superman asked Batman to keep the ring, saying that he wanted it in the hands of someone he could trust.
During the Zero Hour crisis, Batman came to find Superman to seek an explanation for what was happening. Indeed, Superman received a visit from several
versions of the Batman!
When the Joker poisoned Lois Lane, Superman went to Batman for help in dealing with the Clown Prince of Crime. Batman was able to stop Superman from
killing the Joker when it seemed that would be the only way to find a cure for Lois.
When Clark Kent married Lois Lane, Bruce Wayne (who, as he said, was "not above doing a favor for a...friend") made a wedding present of a very classy apartment which Lois had investigated.
Over the years, Superman and Batman have forged a deep respect for each other, realizing that, although they operate in vastly different ways, their ultimate goals are the same. Clark and Bruce have relied on each other time and again during some of their most difficult adventures.