I heard that Eternal Darkness, Sanity's Requiem is the most underrated gamecube game. I've never played it. But if you're gonna be getting gamecube games and you like the character 'Link' from the legend of zelda series, you might want to get Soul Calibur 2 as Link is a character there.
one of the cool things about the gamecube is that almost every game on it is the most underrated game ever
(unless it was also released on the dreamcast )