Time was, you opened a comic book and you knew where you stood. Grab an Action Comics off the stand, you know it's just gonna be good old Superman standing up for the common man and smashing cars. Pick up Detective Comics, well, you'll be in for some pulpy escapades starring the Dark Knight himself, Batman. Then DC had the bright idea that the two should meet, and things were never the same again. Marvel picked up on the idea and smooshed together a load of their wartime heroes - Captain America, Namor, the original Human Torch, Miss America - into a primitive team called the All-Winners Squad. Since then heroes teaming up became rote. You expected that, at some point, Spider-Man would bump into the Fantastic Four whilst swinging through both heroes' native New York. If Wonder Woman went into space for some reason, Green Lantern would pop up to help. Hellboy and The Goon will go hit zombies together. And so forth. The novelty had worn off for the audiences, so comics publishers decided to inject a little more life into the humble crossover, taking cues from Hollywood. The blockbuster, epic crossover events we know today began in 1985 with Crisis On Infinite Earths, a DC series that pulled in characters from all over their line and had dire consequences for many of them. Since then, you can essentially set your watch to the summer popcorn comics in the same way you can their silver screen cousins: both Marvel and DC (and now other publishers too; this year IDW are bringing the X-Files, Ghostbusters and Ninja Turtles together) rely on the success of their huge, company-wide crossover events to keep them going. Despite being born out of such raw, capitalist desire - if every comic for a few months is somehow tied into it, it behooves readers to buy every other title, so they can get the full story - there are some crossover events that are genuinely enjoyable. From the huge cosmic battles to the quieter character moments and interactions you never thought you'd see, here are ten of the best.