If my GameCube were still working, I'd be still playing it. I loved my little black lunch box (yes, it was black, not purple) and I loved pretty much every game I had my hands on. I think I finished Eternal Darkness like 5 or 6 times, also Metroid Prime wich curiously, it wasn't mine, I never bought Prime 1 and I finished it like it was mine, 2 different people lended me a copy of the game and I finished it on Hard and 100% like 3 or 4 times each.
And yes, I admit that I did enjoyed StarFox Adventures and I dare to say that I finished it 4 times. Wind Waker was simply awesome and it's graphics have aged gracefully, it still looks much better than most HD games today. Metal Gear Solid: The Twin Snakes still has some of the very best real time cutscenes I've ever seen in any game, sometimes it's like watching a Matrix movie with Snake instead of Neo.
Paper Mario: Thousand Year Door was awesome, although I've never finished it, because my sister deleted my save and I reached the last boss... I was so pissed that I simply couldn't play the game again.
I could go on and on, I think the Cube was a great system and it was unfairly overlooked by many people, just like the N64. I still haven't stumbled upon a single Nintendo system I don't like.
EDIT: Now I feel the urge to repair my Cube... I always wanted to play the TimeSplitters games and I want to replay many of my good ol' Cube games so bad...