Xbox's best games are from SEGA. Dreamcast all the way.
Dreamcast of course most of the best games are from SEGA but it also has a ton of shmups. Best version until this year of a console version of MvC2. We all know about Ikaruga but also Cannon Spike or Psyvariar 2. Mars Matrix. Then of course NAOMI the arcade board of DC. Fans have ported some of those and of course Atmoswave. PSO the first console MMO and fans keep it alive to this day. Fans still make games for DC. I like Xbox a lot but DC just has insane library and support for fans. Not to mention it's one of the most innovative consoles ever.