NDS got the normal modes.
Grand prix.
Time trail.
Vs.
Battle.
(+ hidden stuff like mirroring 150cc mode)
And a lot of different cars including a plane like car that is fast like hell...
It also got a new mission mode with bosses etc.

And to top that it got pretty much all levels from previous games so the game itself is a minor achievement.
...and then you add multiplayer support with DS-DS and WiFi.
All NDS games should be of this quality.
But there are like a handful, at most, that beats it. :-P
EAT THAT!
"Death, be not proud, though some have called thee Mighty and dreadful, for thou art not so." | Sonnet X | John Donne