What if Matt Murdoch had married Typhoid Mary?
What if Karen Page had gone legit back in California and found fortune and fame, and thus never came back to New York?
What if it had been Mary Jane who was killed by the Green Goblin?
What if Spider-Man had intervened during the events of Frank Miller's Elektra Saga/Gang War?
What if all the original X-Men (Except for Cyclops and Jean Grey) hadn't left the group shortly after Giant Size X-Men#1?
What if Cyclops and Jean Grey had left the X-Men shortly after the events of Giant Size X-Men#1 but the rest of the original group stayed?
What if the Hulk had killed Wolverine during the fight they had early in the Peter David/Todd McFarlane period? Vice Versa?
What if Scarlet Witch had gotten artificially inseminated?
What if Scarlet Witch shacked up with Wonder Man?
What if Professor X had gotten to Rogue before Mystique?
What if Alex Wilder hadn't betrayed the Runaways?
What if Tony Stark had crashed, burned, and died during the events of the "Demon in a Bottle" storyline?
What if Thor had killed Beta Ray Bill?
What if instead of killing Shiro Yoshida, Wolverine had simply sent all the Yoshida-Kai's dirty laundry to the Japanese Ministry of Justice and let them sort it out?
What if Marc Spector had died in the desert?
What if the events of the last storyline of Moon Knight Volume 2 hadn't happened?
What if Sue Storm had concieved as a result of the one night stand in Namor#50 and then couldn't bring herself to get an abortion?