"Guilty Gear X2", X2 Reloded is the x-box version




Guilty Gear is a series of sprite-based fighting games designed by artist Daisuke Ishiwatari and Arc System Works. It is popular with fans for its detailed anime-style graphics, original characters, hard rock/heavy metal soundtrack, unique gameplay, and its numerous references to Rock and Heavy metal music
In the time following Dizzy's disappearance, the mysterious Post War Administration Bureau began to secretly investigate the Gears and the various fighters of the previous tournaments for their own needs and ambitions. Various powers began to work in the shadows to fight for control of the world, with many leads pointing to the creator of the Gears, a mysterious figure known only as "That Man" ("Ano Otoko" in Japanese). Again, the fighters from before find themselves in events beyond their control, most notably at the manipulative hands of a mysterious villainess by the name of I-No, who is revealed to be a servant of That Man for reasons yet unknown.
source"Capcom vs. SNK 2:Mark of the Millennium 2001"

there is also a gamecube and x-box version



Capcom vs. SNK 2: Mark of the Millennium 2001 is a sequel to the fighting game Capcom vs. SNK.
This game was released on NAOMI hardware in the arcade. It was later released for the Sega Dreamcast (Japan only) and PlayStation 2, with the Gamecube and Xbox receiving an updated version called Capcom vs. SNK 2 EO.
Capcom vs. SNK 2 combines characters and gameplay elements from various Capcom and SNK fighting games, mainly the Street Fighter Alpha and The King of Fighters series. Other elements, most noticibly different fighting styles, incorporated elements from other games as well, such as Street Fighter III, Garou: Mark of the Wolves, and the Samurai Shodown series.
Contrary to the previous game, characters no longer have a specific "Ratio." The player can select up to three characters in a team and give an amount or ratio (up to four) to each as he/she pleases. In console versions of the game, player can choose a 1 on 1 game (like Street Fighter) or a 3 on 3 game (like King of Fighters) in Arcade Mode with the Ratio System removed.
sourcealso look for the latest king of fighters it might be hard to come by i believe the latest one is The King of Fighters XI which i own but it was a japanese release only, the latest USA, and Europe version i think is King of Fighters Neowave which is very good.