I would still personally prefer a new game, something completely fresh and novel, instead of a remake of an existing game.

The Switch has a LOT of old games and not enough original ones.

Super Mario Odyssey 2
Super Mario Strikers
Super Mario Party 2
Diddy Kong Racing 2? Super Smash Kart? Mario Kart 9? One of these.
Super Mario 64/Sunshine/Galaxy Remake
Mario RPG (Paper/Mario+Luigi/Other, doesn't matter which as long as an RPG)
Pokemon Remake, perferably Diamond+Pearl but any of the others is fine too, just not a let's go title.

Maybe a new Donkey Kong Country game too.

Excellent list.  The only thing I would add for myself would be a more diversified sports lineup from 3rd parties.  I am extremely happy with the annual NBA 2K releases.  It would be great if EA would put it in at least 1 effort on Madden.  And, I'd take a port of Power Pros baseball from Konami even without the MLB license.

Nintendo needs to make the NEW 2d mario game. The console is perfect for 2D platforming and, as a WiiU owner I've never played a new original 1st party 2d platform yet.

Pokemon Gen 4 remakes - with all Platinum's features, and additional stuff too.
Pikmin 4
More new Dragon Quest games - be they 12, a remake of an older title or whatever.
Another Fire Emblem or two (Genealogy remake, 3H sequel)
Super Mario Galaxy 3
Mario RPG (Either a sequel to Mario RPG or a new Mario and Luigi).
Mario Hoops sequel
The Sims
Earthbound series remaster (I would also like a fourth game, but realise that's not happening)
Octopath Traveller 2
Pokemon Colosseum/XD remasters

Brand new 2D Mario (enough of the NSMB stuff already) 
F-Zero
New Mario Kart (maybe try something different like a more open world Horizon-esque style, or at least Diddy Kong Racing vibe)
Rhythm Heaven
New Monkey Ball
Eternal Darkness
New Mario RPG
Golden Sun
Wii Sports type game
Mario Strikers
Crazy Taxi 
Grandia sequel
Space Channel 5 (yes seriously)

Every Fire Emblem game, every Ys game and every Trails game.

This is a contradiction in the same line as the suggestion.

I s'pose I should clarify - I mean a brand new 2D Mario totally absent of the same old lame NSMB assets/structure/branding. A completely new ground-up 2D Mario, but ideally with more production value, depth, and new environments. Ie no more "water world," "desert world," etc. Something in the vein of DKC Tropical Freeze or Rayman Legends would be a start.

A new F-zero.
Remaster of Mario Galaxy (I would prefer this over a new Mario Galaxy)
All top 50 games for N64 and Gamecube for Nintendo online (excluding the sport games (fifa, madden etc).
Remakes of all MArio + Luigi games (I never played any of them).
A completely new Starfox
Kid Icarus
A new Advance Wars
Octopath Traveler 2 (with more focus on good stories)
Dark Souls 2 and 3
All Batman Arkham games
Mario and Rabbits 2 without the irritating puzzles at the end of part 1 (:P)
Zelda Wind Waker (still didn't play it)
WII U Mario 3d world
Nier Automata