Ocarina of Time, for one reason only. Full camera control.

The N64 had only one analog stick and OoT did not use the c-buttons for the camera (unlike Mario64), meaning to adjust the camera it was all Z-triggering to get the camera behind Link all the time. At the time I did not know any better so this was fine, but boy does it feel janky today.

Even the 3DS Remake did not address it, because the original 3DS also had no 2 analog inputs (circle-pads). So here it was using the shoulder button to constantly get the camera behind Link. Cramp in my hands was a constant reminder playing this version of the game.

So even if it's a quick fix remaster. An HD version of OoT 3DS, nothing fancy. BUT with the second analog stick controlling the camera. For me, a game changer.

KOTOR.
It's one of my all-time favorite games and I want the remake which has been in radio silence for a long time and might be cancelled.
If it still happens, I'm expecting it to be cross-gen with PS6. If it was coming 2026 or sooner, I think we'd know more by now.

Maybe in the Tears of The Kingdom engine? That had a way better camera.

Other: Xenogears

Although, perhaps it would have to be a straight up HD2D port, as remaking Xenogears into a full 3D Xenoblade style game would be a significantly larger game than Monolithsoft (or Nintendo) has ever made. XCX and Witcher 3 have the largest cities ever on a Nintendo console: New LA, Novigrad, and Beauclair - I see those as rough equivalents to the cities of Shevat, Nortune, and Bledavik in Xenogears. But then they would have Oxenfurt sized cities like Dazil and Nisan. But that's ignoring the big one, the country of Solaris, which would be significantly larger than any of those cities.

The original Xenogears didn't have that big of an explorable area because it did the Chrono Trigger thing where it allowed access only to specific parts of much larger cities; but in Xenogears the cities were far larger, and the explorable areas were also far larger. The thing is modern design philosophy where if you see it you can go there. Monolithsoft wouldn't leave those areas as background. This leaves two choices: 1. the player would be able to go everywhere meaning the largest city building dev task off all time, or 2. a compromised vision - which would kind of defeat the purpose of a remake in the eyes of most Xenogears fans (as Xenogears is already famously a compromised vision).

I've been thinking of the Yggdrasil in a modern scale design. Holy crap that thing would be awesome. I think the closest thing we have to a city in an Airship is Skies of Arcadia - the Delphinus.

There's an ocean-going ship city called the Thames in Xenogears, and Xenoblade Chronicles 2 has something similar (if I remember XC2 correctly).

The Zeboim civilization ruins would be phenomenal. But what I'd really like to see is a fleshed out city to explore during the 4000 year old flashback sequence - I doubt it would happen - probably like Tir Na Lia in Witcher 3, which is kind of like what the scene is like in Xenogears. Morytha in Xenoblade Chronicles 2 is also similar to Zeboim Civilization, although it comes from a different part of the 10000 year old timeline. In Xenogears, the beginning of the timeline is similar to Xenoblade Chronicles X where a giant spaceship crash-lands on a planet, and 6000 years later Zeboim civilization had developed - a metropolis-level and then apocalypse... where Morytha was destroyed by its apocalypse about 10000 years prior and there's not really anything about the build-up.

But anyway, a remake of Xenogears would easily be the game I want most of any game. Without compromise.

Here we go again ....

Are we specifically speaking of a visual remake ? Reimagining? Reboot?

The definition of what a remake or a remaster is knowdays is completely out of the norm depending on which publisher you are asking those questions but anyway.

Personally, considering the history of what Xenoblade Chronicles X originally was supposed to be as a project, similar in story structure to Xenoblade 1 before the online and multiplayer elements came into the mix. I feel like it'd be quite grateful for Takahashi to re-explore the original vision he had for the game's narrative structure with a remake.

You keep most of the open world structure of the WiiU version but remodel certain elements or add on top of it to make it just into a more palatable experience for newcomers, just like Xenoblade DE and Xenoblade 3 did.
Or at least add a freaking epilogue like you did with Future Connected for XC DE.

Side Quests structure doesn't need to change much, but it might be wise to not gatekeep story progression to exploration/affinity quests milestones.
Of course, take advantage of the Switch 2 capabilities to actually make it a better looker instead of pulling off the biggest visual cheat in the existence of Open World games.

Mother Trilogy (they are unplayable with the rate at which random encounters occur), Zelda Ocarina of Time/Majora’s Mask, Super Mario 64. The original Super Mario Bros Trilogy could also be remade, I feel many ideas could be thrown in there so as to breathe “modern life” into the games.

Someone mentioned here, OoT got a remake on 3DS. If ya got one lying around. 

I forgot to mention, many people might not know that MGS1 already got a remake, one where Kojima was involved in Twin snakes on Gamecube. People, myself included til a few years back, think this is a simple port but no, it's reworked in the MGS2 engine and adds/changes a load of stuff including cutscenes. 

Duke Nukem 3D to make up for the embarrassment that was Duke Nukem Forever.

3D Chrono Cross would be amazing