Phantasy Star Online
From Sega Retro
An MMORPG made by Sega for the Dreamcast. This one has a lot of references to past Phantasy Star games. PSO was also released for Gamecube and Xbox (and was one of the only online games for Gamecube). Both sequels, episode 2 and 3, were made for Gamecube. Episode 3 was never released on Xbox.