Dragon Quest Heroes Rocket Slime.
Plays like L2TP and Minish Cap. Has a recurring and engaging side game (tank battle) that I love. Quite possibly my all time favourite game on the DS, top 5 at least.
Freshly Picked, Tingles Rosy Rupeeland.
Well its a spin off so its got Zelda references all over. Quirky gameplay that can take some getting used to. Its often dismissed as a game for queers by ignorant young males but given a fair go the humor is good, the gameplay is fun and you can still laugh at Tingle's misfortunes despite playing as him this time (its an origin story).
Also worth a look: Mario & Luigi - Partners in Time, Summon Night -Twin Age, and just because it doesn't get mentioned often enough Lock's Quest. Its not at all like Zelda but its worth a look despite its flaws. An excellent start to what could become a genre leader.