Exactly what the title says.
For example a crossover between Chronicle and Infamous (both deal with the premise of "superpowers in the 21st century", has a reluctant hero as one of the protagonists -Matt Garetty for Chronicle and Cole MacGrath for Infamous-, and both show the consequences of how that kind of power would affect society.)
Athough the problem with this idea is that there's very few video games/movies/tv shows/comic books that have anything in common with Infamous.... :(