I'm shamelessly making a similar thread to @curl-6 but I think this is also a topic worth discussing. Which Nintendo handheld after the Game Boy introduced the best franchises?

Game Boy Advance: Kururin, Golden Sun, Starfy, WarioWare, Rhythm Heaven

DS: Nintendogs, Brain Age, Big Brain Academy, Clubhouse Games, Personal Trainer, Fossil Fighters, Tomodachi, Art Academy

3DS: Steel Diver, Pushmo, Dillon, Fantasy Life

Switch: Arms, Labo, Ring Fit Adventure, Astral Chain

Please let me know if I'm missing anything. The IP in question needs to have at least two games, regardless of whether or not they had a worldwide release.

Hmm, none?

Isn't Ring Fit part of the "Fit" franchise?

lol Yeah, not the greatest track record for the handhelds.

I will go with the GBA though. I love Rhythm Heaven and WarioWare.

Switch. Astral Chain. Best new ip for Nintendo since Xenoblade.

A lot tougher to decide than the home console one. Though not because there’s so many great stuff of all-time classics in there, but because I barely played anything of all these and none of them are what I’d call A+ tier. Anyway, I actually played Brain Academy and the WiiU Art Academy so I pick DS.

Astral Chain makes Switch the clear winner to me.
GBA is second for Golden Sun.

I'm not sure if Advance Wars and Fire Emblem count as new on the GBA or not. They were new to everyone outside of Japan. If I can count those, then it's the GBA. Otherwise I'll have to go with the DS.

Astral Chain makes Switch the clear winner to me. Easily.
GBA is second for Golden Sun and Warioware.

Everthing else is just meh.

Advance Wars was not a new IP on GBA btw. The series dates back to Famicom with Famicom Wars.