1. A Death In The Family
The danger inherent in the Joker character had always been hinted at but had never really hit home. Sure, hed killed the occasional innocent and gangland thug and although his heartless attack on Batgirl was shocking, it was uncertain as to whether that was really part of continuity at the time. So in the mainstream comic world, Batman had gotten off fairly easy when it came to his arch nemesis. Death In The Family, of course, changed all that. Essentially devised as a way to deal with the troublesome new Robin, Jason Todd, a character who writers and editorial staff had handled so badly since his introduction, that the general readership couldnt stand him. Enter the Joker and a 900 number. After beating Todd near to death with a crowbar and then blowing him up (along with his mother) readers were asked to decide whether Jason would live or die come the next issue. Much to DCs horror, the readers voted for death and so it was that, not only was an iconic Joker moment born (the murderer of Robin) but the powers that be learnt to perhaps better manage their sidekicks.