X-Men vs. Street Fighter

X-Men vs. Street Fighter was the first Capcom crossover to put Marvel mutants and world warriors on the same roster, and the first to build its fights around two-character tag teams. You pick a pair, swap them mid-combo, and call an assist while the other recovers, which is where the series' trademark screen-filling chaos begins. The PlayStation conversion had to trim the arcade's simultaneous tag mechanic to fit the hardware, but it keeps the enormous supers, aerial rave combos and the exaggerated speed that made the arcade board a phenomenon.