A crossover is when one character from one storyline enters the storyline of another, be it from game to game, cartoon to game, movie to game, etc. Whatever the situation may be, they often come off as cheesy and like marketing ploys. Sometimes, though, they're great, so we've come up with a list of the best crossover games.
http://www.ranker.com/list/the-best-crossover-game/son-goku,
Battle Stadium D.O.N
Sunday VS Magazine: Shūketsu! Chōjō Daikessen
Mortal Kombat
Dead or Alive: Dimensions
Ultimate Marvel vs. Capcom 3
Street Fighter X Tekken
Scribblenauts Unlimited
Project X Zone
PlayStation Move Heroes
Asura's Wrath