If we're counting fan remakes, I'd say Open Transport Tycoon Deluxe was one of the best. It was a game I loved from the 90s but it began aging rather poorly as it had a number of bugs and odd limitations. then the Transport Tycoon Deluxe Patch was created and it fixed so many issues but that eventually hit a wall and couldn't be taken any further either. And then the game was completely recreated by fans and this remake has been getting regular updates for 13 years. It's very good. And even has a strong modding base where you can actually download mods for the remake. Here's the link if you're interested:
https://www.openttd.org/en/
Yeah I think we should include fan remakes.
Streets of Rage Remake
Fantastic remake that blends all three games into one. There's a level route following each game, it's possible to diverge however, for example you can be at the Streets of Rage 2 bar and end up on the Streets of Rage 3 train level.
It also features new levels. The soundtrack is amazing too.