Kirby: Canvas Curse is a good bet. The stylus-only control scheme is very intuitive, and there's something particularly immersive about leading your character around on a path you draw yourself. And the level design always finds a way to complement the controls; each stage has some kind of unique gimmick, so the gameplay never stagnates. There's also plenty of replay value in the way of hidden medals hidden throughout stages, special challenges, time attacks, minigames, and five different playable characters.