5) Identity Crisis
​Again, I'm talking about what matters, not necessarily what's good here, so I have to bring up Identity Crisis because of its continuing influence on the DC universe, in its need to be Dark and Adult. It'd be hard to imagine a DC where superheroes could torture people like they did in Cry for Justice or have crazy hallucination sessions with dead cats as in Rise of Arsenal without the prominent rape scene and heroes-being-jerks plot of Identity Crisis.

4) World War Hulk
​This series is important for one big reason, aside from it being pretty good: It didn't introduce Amadeus Cho, Marvel's best new character of the last decade, but it really burst him onto the scene in a big way. Also, it spun off the Incredible Hercules series, which isn't around anymore, but dang, it was good. That matters, right?

3) Infinite Crisis
​For all the arm-rippings and head explosions and punching-through-reality in this series, the one real, lasting effect is the return of the multiverse. 52 worlds! One of them is the Watchmen universe! This is absolutely going to be kind of a mess!

2) Spider-Man: One More Day
​The crossover that ended Peter Parker and Mary Jane Watson's marriage forever with a simple snap of Mephisto's fingers will forever be notable as possibly the event that resulted in the most pissed off fans in history. But you know what else it resulted in? The best Spider-Man comics in like 25 years (though many have argued that those comics could be more or less the same, with the marriage intact). Still, three years after the big change, Marvel shows no signs of restoring the marriage.

1) Final Crisis
​Lots of readers found Grant Morrison's year-long megaseries which reshaped Jack Kirby's Fourth World, included crazy characters including the Japanese Super Young Team and ended with Superman singing the universe back into existence, hard to follow and confusing. But the part that matters most is pretty easy to grasp. Batman kills Darkseid with the radion bullet; Darkseid shoots Bruce Wayne with Omega Beams. Those beams send him hurtling through time. Long story short, Batman went through a lot of crap, traveled to a bunch of different times, came back and decided to incorporate. What I'm saying is because of Final Crisis, there's now a Muslim Batman of France. And that definitely matters.