Gamecube was a solid system but it isn't underrated by any means. People realize it has a few quality games (and in Melee it has one of the best games OF ALL TIME) but that doesn't take away from the fact that it had a lackluster library of games on the whole. This is especially important because it competed with arguably the greatest console of all time, the PS2, so there is no way the GC was going to survive.
Oh, AND WHY HAS NO ONE TALKED ABOUT ETERNAL DARKNESS IN HERE YET!? That is the real underrated item in this thread..
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http://gamercards.exophase.com/4831.png
http://i51.tinypic.com/2zpi5w4.png <-- How I look as per Clogged_Artery (Thanks!)