I believe the only question would be is there a better Nintendo only game for the Gamecube.

User Rating: 9.1 | Super Smash Bros. Melee GC
The Cube was the first of the three big systems I got and the sole reason I wanted it was because of SSBM. I loved the original one for N64 and just had have the sequal even though I could think of no other game for the system I really wanted. Anyways, here's what i think of SSBM.
The gameplay is good. You go around beating the living #@%! out of things which is wha a goo bash em' up game does. I love playing friends on multiplayer. I'd say i'm mediocre to farely decent. Many seem to think it has a week single player mode. Maybe I'm just easily pleased but it seemed to sufice for me. My big problem is there are some serious issues with the camera. Often times you're bashing away kicking ass when all the sudden the camera changes becasues another person moves in and you can't see what the hell you're doing.
The graphics are good. not much to talk about and I would expect a fighting game to be the most graphicly detailed since you usually have little time to survey the scenery.
The sounds good with nothing speacial. every now and then some niffty music comes in that can be nice but nothing more.
If you have a gamecube, it'd be a good choice beings how it's one of the few good Cube only games.
I love this game and would recomend it to anyone with a Gamecube. Of course you'd be unlikely to run into someone that owns a Gamecube that didn't have SSBM because it just kicks that much ass!