List of works currently in the running for the “Biggest/Most Ambitious Crossover of 2018″ award:
Avengers: Infinity War
Crossover between: every Marvel Cinematic Universe movie up to this point.
Super Smash Bros Ultimate
Crossover between: every video game previously part of the Super Smash Bros franchise, plus some new ones.
Ralph Breaks The Internet
Crossover between: everything owned by Disney (including Star Wars and Marvel)
Ready Player One
Crossover between: here’s the list.
OK KO: Crossover Nexus
Crossover between: every Cartoon Network show ever made, including some of the live-action ones and at least one made-for-network movie.
Anything I missed? Let me know!