overgeeked
B/X Known World
Regular What If? / Elseworlds stories about all the characters, especially focused on the crossover. What If Bruce Wayne was Iron Man? What If Wolverine became Green Lantern? Etc.
Proper Best of the Best roster for the Avengers / Justice League.
Expanding the X-Men to include all the weird obscure mutant-like characters in DC.
Have Nightcrawler bamf over to the Legion of Super-Heroes where he was originally meant to be. Even if only to say hi.
Have a knock-off knock-off event. Even if only a What If? / Elseworlds story. Pair off all the knock-off characters and have them knock each other off until there's only one standing. All the Superman clones fight until there's one left. All the Batman clones fight...all the Spider-Man clones fight. Etc.
Expansion of the Amalgam and Tangent comics lines. They had some of the best characters and stories.
Teen Angst-a-thon. Mix and match and teenage drama fight all the "special high school" characters across both brands.
Pair off some of the best villains with the best characters. Batman's or Flash's rogues gallery vs Spider-Man.
Punisher and Peace Maker go on a date.
All kinds of things.
