Legend of the Twilight Anime is a terrible terrible creation. It falls into the stupid trap of cliche anime to the nth degree. I love the original inception of the series. I didn't much care for the G.U. anime series as it felt too long with not much going on and subpar animation. I know SIGN didn't have a whole lot going on but it felt like they were uncovering a mystery and making progress and by the end something was accomplished. It was a complete story for the characters involved while G.U. felt like a set up to get people interested in the game.

EDIT: I forgot, SIGN has by far one of the greatest soundtracks of all time.