Don’t listen to SG, he’s a poopoo head. Hotel Dusk is a pretty decent classic adventure game, which is quite obviously not his genre. The gameplay is indeed a bit lacking, but that’s pretty much why adventure games are dead these days, no? It does have pretty faptastic art and the plot is amusing, so worth checking out if you’re into that sort of thing. Alternatively, SCUMMVM DS + old Lucasarts games.
Ouendan/Elite Beat Agents/Ouendan 2 - crazy music games made by insane japanese people. None of it is original music, and only EBA can be bought locally (playasia.com for imports). They are, however, fantastic games with a lot of crazy japanese quirks, and somehow manage to make the most awful songs possible (La La) into incredibly awesome stages. I think I’ve spent more time on these games than any other DS game, and that’s saying something.
Etrian Odyssey - Dungeon crawler. Very good dungeon crawler. Very hard. Great if you’re into them, you will staple your cock to your chin if you’re not.
Mario Kart DS - Best Mario Kart, period.
Cooking Mama - Really fun, if shallow, game. Basically a series of minigames to cook dishes. I got half my class addicted to this game and as a result I can’t play my DS in class anymore
Pokemon - Great Pokemon game. It’s Pokemon, there’s not much to say. A lot of mechanics were reworked, causing every Pokemon to have a wildly different functional moveset. It’s possible to get every pokemon ever in these games, though that’ll require the old GBA games or trading online (best feature EVER). Hit me up for starters if you get it.
Trauma Center - I don’t think you have a Wii, so I’m gonna recommend the DS version. It is a fantastic game, not realistic at ALL (virus that fires lasers wtf) but incredibly fun. The operations are pretty diverse and can be stupidly hard at times. From what I’ve heard the Wii version is better in pretty much every way, but the DS game is still very, very good.
Kirby Canvas Curse/Power Paintbrush (whatever it was called over there) - Pretty fun platformer, uses the touch screen in a pretty cool way. Should be cheap now, grab it.