I know Nintendo isn't fond of remakes but...

 I believe that an updated remake of Metroid Zero Mission, a port of Samus's Return, an enhanced remake of both Super Metroid and Metroid Fusion could hold off Metroid fans for a little bit...

I also believe that The Era of Decline in Zelda could be remade into a Full updated story.

I also have a soft spot for the "American Zelda Clone" by Nintendo of America, Startropics. It seems largely forgotten... it would be nice to see at least the OG NES games in the NSO NES... but I'd give my left nut for a 3D remake.

Same thing I'd say for the Super Mario Land Games... 1, 2, and 3 with DLCs... 

Hear Me Out:

Super Mario Land DX. SARASALAND SUPER ADVENTURE. The first 4 lands start as in Traditional Super Mario Land. After you defeat Tatanga on the Final stage of the 4th Land, Kamek shows up and transforms Tatanga into Ultra Tatanga 64 who takes Daisy again. Mario must enter 4 new Kingdoms to locate Tatanga once again.

HYRUFA Kingdom: a pseudo Celtic kingdom with Hyrulean elements/enemies. (Reference to Link's Awakening having Mario elements/enemies) The boss would be a "not ganon"

JIGURAPICHU Kingdom: a peruvian jungle themed world. THe boss would be Triclyde

SHIBETRIS Kingdom: Inspired by Russian Folklore AND Tetris. The boss would be a bear.

MUSHROOM Kingdom: A familiar place turned into a gauntlet. Each level has a boss: Level 1 you have to face Kamek. Level 2 has Tatanga controlling a Mecha Bowser whose design is based on SMB1 Bowser. In Level 3 you take to the sky to defeat Ultra Tatanga 64. Once Ultra Tatanga 64 transforms back to normal Tatanga, you must defeat him in order to Rescue Daisy and take her back to SARASALAND.

The DLC would be Super LUIGI LAND!!

Same DX game but with SMB2 Luigi's floaty physics.

Super Mario Land 2: Six Golden Coins DX edition in essence would be the same game as its Gameboy counterpart. The main difference is the addition of 3 new zones. These zones cannot be accessed until Mario gets the 6 L-Keys. The idea is that once Mario has the 6 L-Keys, he can re-enter the Mushroom Zone and access a brand new Secret Exit for the New Zones he was working on for Luigi's own Land. These would be like a short demo for the DLC.

The DLC for SML2, would be SUPER LUIGI LAND 2: SIX GOLDEN AND SIX SILVER COINS. After Mario defeated Wario, He goes on a quest to find the Brown Sugr Pirates and recover the Princess Peach statue. Luigi ends up house sitting for Mario. All Hell breaks loose when Kamek steals the Golden Coins from Mario Land. When Luigi beats the first boss, he discovers that the coin is a Silver coin for Luigi Land's L-Bridge. Once he beats both Mario Land and Luigi Land, he returns to Mario's castle to find out that Waluigi has taken over.

Wario Land DX: Super Mario Land 3 would get more stages and treasures. The DLC would be Waluigi themed. Waluigi is slim so he lacks the tackle and butt stomp from Wario, but instead he gets a drill torpedo attack similar to Luigi's missile from Smash that can be used horizontally or straight down.

Before anyone comains about this, I used strategies that Nintendo kinda used before.