Good GameCube games

[AwesomeYears]

The Simpsons: Hit and Run was always a favourite one of mine.

[Magic Mole]

Pokemon XD: Gale of Darkness is a must-have if you like Pokemon games.
Not sure if you're into Sonic games or not, but if you are, Sonic Adventure 1 & 2 are both great (1's not for everyone but I absolutely adore it). Collections like Sonic Mega Collection and Sonic Gems Collection are also amazing if you like the franchise. Sonic Riders is super fun too.
I have fond memories of Prince of Persia: Sands of Time, Starfox Adventures, Sphinx and the Cursed Mummy, and Billy Hatcher and the Giant Egg to name a few.
If you play with friends a lot, Cel Damage, any Mario Party (6 was my favorite), Super Mario Strikers, etc. are all great for that.
Those are my recommendations for now. I purposefully left out most of what others said previously.

[Olimar12345]

Pikmin 1 is on Wii, so that's a thing.

It would be worth investing in the GCN version, I can assure you. It's quality is far better.

[mikey]

TLDR any gamecube game is good

[Olimar12345]

TLDR any gamecube game is good

Proof that this statement is false:

Spoiler

[close]

[mikey]

Starfox Adventures

Also Pokémon Coliseum (Colosseum?)

[JDMEK5]

Proof that this statement is false:

Spoiler

[close]

But dude, StarFox Adventures was alright. Solid game. I liked it.

[Olimar12345]

But dude, StarFox Adventures was alright. Solid game. I liked it.

^ guys, we need a new JDMEK. This one is defective.

[JDMEK5]

Lol I mean, it was definitely different than the usual StarFox genre, but as a game in and of itself, I thought it was alright.

[Dude]

I liked it too...

[braix]

I have memories of playing Metroid Prime 2

Spoiler

it was aight

[close]

[SlowPokemon]

Luigi's Mansion is my favorite GameCube game.

[Nitro Indigo]

Let's see... for starters, I need to make a list of things that interest me. All of the prices are from Cex.
Wired controller: £15 (cheaper than I remember...)
3rd-party memory card: £1.50
The Thousand-Year Door: £50 (why is this not under Keep Circulating the Tapes on TV Tropes?!)
Enter the Dragonfly*: £8 (exactly twice as much as it was on PS2, and it has a four-star rating for some reason...?)
Pikmin 1: £8
Animal Crossing with memory card (apparently) - £25

After looking through their entire GameCube catalogue, I discovered that most of their (second-hand) stock is licensed games. The actual first and second-party games are really expensive (Path of Radiance is £100), with a few exceptions, such as the aforementioned Pikmin. According to TV Tropes, Pikmin 1 on GameCube is really rare and expensive...?
If I'd known that A New Beginning was on GameCube, I wouldn't have re-brought a PS2 just to play it after seeing it mentioned on TV Tropes a few times.

*I know most people don't think highly of this game, but I once read that they fixed the game when they ported it to GameCube. I'm not sure how true that is, but I kind of want to finish something I started, though not as soon as possible.

I think I found the best game title ever.

PS: Why aren't GameCube games on Wii U VC yet? Is it because of ~compatibility issues~? *cough*GBA games on 3DS*cough*

[SlowPokemon]

@"best game title"

you're wrong

[Nitro Indigo]

^ I actually laughed at that. XD