Upgrade that Tetris from the Original to Tetris DS.
As a borderline obsessed Tetris fan, that has to be THE MOST PERFECT version of Tetris released ever in recent memory.
Also
- Brain Age if you like Sodoku, fukk with it until that unlocks and chuck all the other game modes to the bushes.
- Final Fantasy Tactics Advance.
- Yoshi's Island
- GTA China Town Wars on either PS Vita or DS
- Damn near everything in the DS Super Mario rpg series.