If you're in the camp that thinks NX is the 3DS successor and releasing 2017,what 1st party games are left for it? 

I think Rythmn Heaven The Best+ western release,Pokemon Z,new Kirby,spinoff title

Theres still the paper mario croosover
too late for pokemon i think it might be crossgen
Federation force FTW
i dont think anything more

You mean aside from the half dozen or so announced titles, I assume? Presumably not much, I'm afraid.

Mario & Luigi: Paper Jam
Fire Emblem Fates
Hyrule Warriors Legends
Metroid Prime: Federation Force

Those are the announced titles with localizations of games like Rhythm Heaven, Style Savvy 3, Picross 3D being possible and Pokémon Z seems inevitable.

Hmm, besides the games that have been announced, I'm not expecting much.

I'm hoping to see Rhythm Heaven localized, and I am expecting to see Pokemon Z, but after that, I don't expect anything too major.

Still probably gonna get a new Pokémon title.

Other than that, I see nothing big on the horizon. When you consider the fact that they dropped the ball with Wii U support post-launch, they should be putting 100% focus on making sure the NX has a healthy lineup of titles.

federation force (I'm ready to watch it suffer) 

Hyrule Warriors

That new Paper Mario

... that's the 3 I can think of right now. 

Aside from the already announced titles, there probably is still Pokemon Z / X2Y2

..and maybe a spinoff game. Not much really

It could also be Pokemon XY& Z or XZ YZ...:p

The new Mario and Luigi game, Federation Force, FE Fates, maybe pokemon Z,and one or other game that I dont remember now.Yeah, counting just first party, there is not much