Street Fighter IV - Balrog Vs Chun-li
Well, you probably know him as Vega, actually. Apparently this is all due to a potential legal wrangle over the boxer, named Balrog in the Western releases, who was called M.Bison in the Japanese original. He was allegedly thusly named because his character was based on Mike Tyson. The potentially damaging lawsuit was averted by rotating the names, hence all the confusion.