Perhaps it's the availability of the new interface, but both games I've played so far on the Nintendo DS are classics. WarioWare: Touched is a gallery of 100 ways the stylus can be used. Until you beat the game itself, it's rubbish to play--it's just too easy. But when you have all the levels available, and the characters representing them are wondering around the screen, and new high scores are giving you yet more toys and levels, and the game is teasing you to get you to play harder... then WarioWare comes into its own. Until then it's a game for game and interaction designers.
Project Rub, on the other hand, as well as looking stunning, has the best storytelling play I've encountered.
The main game is a love story played through a number of scenes. Each scene has up to three subgames, like having to jab scorpions off the girl's back, or ride a unicycle. You start off just trying to impress the girl, then you hang out, then you have to rescue her, and there's a big boss at the end. Every so often, inbetween these faster subgames, there's a love scene, and you shift from being very active to having to very slowly hold the girl's hand with your stylus. Beautiful. (You can read about the levels in this walkthrough. As you play, you also collect different outfits you can dress the girl in, in Maniac mode, and she appears like that at the midgame scorebaord. You can touch her, and she gets indignant.)
Here's the absolute best bit: The game gradually speeds up towards the end. You don't get breaks between the last few subgames, you don't know what's happening next, there are fewer save points, you have to repeat levels on a harder setting. Until, finally, there's a level which is all about moving your stylus as fast as possible. Right, so you're as active as you've been in the game. You literally can't put it down otherwise you'll forfeit your position.
Now comes the last level where [spoilers] you have to bring the girl back to life with heart massage and mouth-to-mouth. The level jumps between three actions, each lasting a few seconds: tapping the screen gently at the same beat as her heart, tapping the screen madly to scare Death away, and blowing onto the screen at the rate of the girl's breath. The breaths are repeated so you can't just take one big breath and let it out in little puffs: you have to synchronise your own breath with the rate on screen. Then the breathing rate you have to do increases, and suddenly the game is making you breathe faster--and you have to hold your head really close to the screen for the entire subgame, just incase it jumps from a heart tapping to breathing action. The level, while simple, suddenly becomes ultra immersive and physically adrenalising, your body responding to your faster breathing by getting exciting! It's a gameplay trick to influence your perception of the narrative as clever as loud sounds and flashing lights in a movie to hype you up, and it's woven into the story perfectly.