Eternal Darkness was a brilliant game alright.
You know, I still own the game and haven't played it yet.
I can't seem to remember to find the time to play that masterpiece.
What I mainly played was Melee(Still playing it), Super Monkey Ball 2, MK: Double Dash, MGS: The Twin Snakes, Wind Waker, Twilight Princess, Mario Power Tennis, Metroid Prime, Pokemon Coloseeum, and played my friends, copy of both Viewtiful Joes, and Paper Mario: The Thousand Year Door.
The GC was amazing and had good third party games. It's a shame their exclusivity was usurped.
Both the Super Monkey Ball games were ported in 2005 in the form of Super Monkey Ball Deluxe for the PS2 and Xbox(GC version was still better due to the loading times on Xbox and frame rate on PS2), both Viewtiful Joes were ported to the PS2, and RE4 went to the PS2 as well.
What great third party content it had was taken away.
The PS2 still has the best third party content, don't get me wrong.