One of the first games ever released for the Dreamcast, and one of the best, Soul Calibur is amazing from start to finish.  The graphics, control, special features, and fighting engine are superb, and this is the one game that if you own a Dreamcast you must have this as well.  However, good luck finding it, when the Dreamcast came out, it sold pretty quickly, and Namco only released the game in limited quanitites, but this is one hell of a game, and its a better investment to buy a Dreamcast and this game rather than lay down 50 bucks for a single game on any of the other systems.