Look past the cel shading ( which was still very pretty)
I'm currently playing it on the dolphin emulator for the first time. It likely doesn't look that great on a Gamecube, but emulated at 1080p with anti-aliasing and this game is absolutely gorgeous. I find it hard to believe that it is a 10 year old game.
I missed out on WW when it first came out because of the graphics, but now I can say that they are beautiful and have stood the test of time. Also a fantastically fun game.
As for the gamecube, it had the best graphics of that generation, the best controller of that generation (imo), and a solid library. Not sure why it was overshadowed by the PS2.
Super Smash Bros
Mario Kart Double Dash
Metroid Prime 1 & 2
Star Wars Rogue Squadron
Phantasy Star Online (Dreamcast Port)
RE 0, 1, and 4
Tales of Symphonia
Skies of Arcadia (Dreamcast Port)
Super Mario Sunshine