Help me come up with some recommendations for a new DS owner who prefers retro games

My friend Simon, who runs the lovely retro-focused game blog called Red Parsley, recently reached out to me to share the joyful news that he's now the proud owner of a Nintendo DS.

Unsurprisingly, he also asked if I could offer up a few DS game recommendations.

I did just that late last night. Specifically, I said he should consider picking up some or all of the following for various reasons I won't go into here:

9 Hours, 9 Persons, 9 Doors
Bangai-O Spirits
Big Bang Mini
Contact
Dragon Quest IX
Hotel Dusk
Kirby Canvas Curse
Mr. Driller: Drill Spirits
My World, My Way
Pac-Pix
Puzzle Bobble DS
Retro Game Challenge
Rhythm Heaven
Soul Bubbles
Taiko no Tatsujin DS
Tetris DS 
The World Ends with You
Yoshi Touch & Go

Although I have a feeling all (or at least some) of the games mentioned above could keep Simon and his new DS busy for a long time to come, I also think it couldn't hurt to send him a few more suggestions.

So, I'm asking all of you: which DS titles would you recommend to someone who is new to Nintendo's first dual-screened system and who tends to prefer games of the "old school" variety?