The Gamecube was definitely a great era. So many great games, it's hard to just choose one. Luigi's Mansion was something that was new, shed some light on Super Mario's bro, unique, and just very fun. I loved the atmosphere and the music it had, it was just a great mix. Seriously one of the Gamecube's best games. Then we have Resident Evil REmake, a masterpiece. A remake to a great game that hadn't aged very well. For those who have played the original, were really in for a nice surprise. Newly added content, completely overhauled graphics that show a great level of detail that really bring out the atmosphere, awesome twists to get those cocky players of the original scared for example, the crimson head zombies, etc. Resident Evil REmake is everything a remake should be. Speaking of Resident Evil, we also have Resident Evil 4 which is yet another masterpiece. It defined 3rd person gaming that later inspired such games as Gears of War and Dead Space. It was full of action, intense moments, some scare factor, and plenty of WTF moments that are pretty easy to miss. It's the game that has you discovering new things with every playthrough. Metroid Prime would have to be another one of Gamecube's top games. It had some of the nicest graphics the Gamecube had to offer, and it was totally new and unique. It took Metroid into 3D gaming and just evolved it. It was a first person adventure game with plenty of memorable tunes. Metroid Prime is certainly the first of it's kind. And then there's Super Mario Sunshine. Now that's a game that was very underrated. I loved the music, the deeper story that I wish would return in future titles, innovative gameplay(thanks to FLUDD and Yoshi), and the very cool and new environments in which the game took place in. It was so different from what we're use to seeing Mario in, it was a nice change of pace. And who can forget Eternal Darkness? It was scary, creepy, innovative, different, new, it was everything you'd want in a game. Each level took place in a new location with a different character and time period so it always felt fresh. The best thing about it was seeing how each character connected and getting to see how each location changed when you revisit it with a new character. The insanity meter was also a very nice touch, it kept things interesting and scary.
And of course, we have The Legend of Zelda The Wind Waker, The Legend of Zelda Four Swords Adventures, and The Legend of Zelda Twilight Princess. I think those games are already spoken for... So yeah, it looks like a very hard decision. How can one possibly just choose one game from the Gamecube's amazing library of masterpieces?