Rings of Fate is pretty fun, especially since i enjoyed Diablo, i enjoyed playing this with my friends.
Ninja Gaiden is also pretty fun, and i love how flashy it looks xD
Still waiting for F-Zero though.... Hope we get some news on it quick...

GRID is good, but it looks and i suppose it will be, like most of the other generic racers like NFS, etc.
The ability to make your own race track sounds pretty cool though, but i don't know how much that can contribute to online play, will people be able to download the map you've made, and use it for multiplayer online?
And anyways, racers like this can't really compare to Mario Kart. Mario Kart has a drift system that generic racers dont use, it adds a different type of skill needed and there's the fun item system to it as well.
(which adds in some strategy to whether you really wanna lead all the way or not or stay in middle ranks for better items, etc)
I'd say Mario Kart is more of a party racing game, which i would say is more fun then generic racing games, but at the same time requires skill and some tactic/strategy.

The graphics cannot improve. If it does, those newer games with better graphics cannot be played on the old DS, only on the DSX (what you call).ALL THOSE THAT SAID SOMETHING SIMILAR

A DSX. what's that supposed to mean? ALL THOSE THAT SAID SOMETHING SIMILAR

Finally, Nintendo can't do that, DS was just released two years ago. ALL THOSE THAT SAID SOMETHING SIMILAR