its been about 5000 years since i last touched a DS so naturally i can barely remember anything from it, but in no particular order these are some of the ones i remember putting an absurd amount of time into:

• tetris ds (obviously)
• EBA (only rhythm game i ever felt the need to S rank everything)
• meteos (better than tetris, imo)
• bangai-o spirits (very funny since apparently zero fucks were given in regard to performance and throwing billions of sprites around the screen)
• a pokemon mystery dungeon (although it didn't totally rewire my brain chemistry like it did some people i know)
• that warioware that was on it (its just good)
• kirby super star ultra (since that was also a fav snes game)

there are probably a lot more but they are eluding me right now