SSB:M does not qualify as fighting. It is its own genre. There is no other game like it. It's a multiplayer fighting action/adventure great thingy with minigames. I've played it. But, it's the only Cube game I've played, aside from Metroid Prime at Best Buy. I played it for about half an hour, and I didn't really like it.
So, the top picks are WW,
SSB:M, Super Mario Sunshine, and Viewtiful Joe, and Mario Kart: Double Dash. Those were all already on my list, except Mario Kart: DD, which I have never heard of.