Which games from the last 10 years do you find the most original and creative, and what about your pick makes it worthy of the top spot?

I think the first one that comes to my mind right now is Undertale.

I still finds incredible how the Pacifist;Genocide routes creates two different stories in a single game. Very creative, and the gameplay is quite refreshing too.

That game's 10th anniversary is in less than two months.

Not a critique of your answer, just a realization I had to share.

Death Stranding. I know the joke about Strand type games and all that but there is no doubt that Kojima created something different here. There simply is nothing else like death Strandings post game loop. DS2 is a little less unique because you can kill people with few repressions and battle BT's quite easily as well as the terrain being fairly easily navigateable by any mode of transport but that first game was wild, just the act of having to manage your balance adds something very unique but really it's the end game loop and the first game that is a sim game at it's core with AAA level production and film like story.

There are a few others like Neir Automata and Dave The Diver that bend genres and a whole load of VR games that there is no point listing cause any VR game done well feels unique and Vampire Survivors which spawned a new subgenre and showed that games can still be feel very deep and bonkers fun without really having to engage with them and yet still deep nor grindy and still feels like an actual games unlike a mobile game.

I could list quite a few but nothing as unique as those.

Oh and a little, lesser known game called Everything that plays with microscopic scales and macro scales of the universe, very unique title.

SUPERHOT for its superb implementation of "times move when you move" mechanics into FPS genre, and GOROGOA for its mechanics of temporal and spatial manipulation of 2x2 grid of pictures to tell a story through clever puzzles.

Viewfinder and Gorogoa

Astrobot: Rescue Mission for its creative mechanics and boss fights. Building on how platformers can evolve further into the 3rd dimension while retaining the simplicity and accessibility of the sidescroller formula.

Moss: (especially Book 2) A new take on the puzzle platformer where the player controls both the protagonist as well as the environment in a natural way. Turning what would have to be a co-op game into an intuitive single player adventure.

And yeah many more VR games that do stuff that simply wasn't possible on a flat screen / with a 'cursor'. For example Synapse using eye-tracking to give you telekenitic powers.

For pure creativity The Midnight Walk is incredible. Stop motion perfection.

Most immediate that comes to mind is Kunitsu-Gami: Path of the Goddess. A Pikmin/Tower Defense game with a hack n slash protagonist set in a gorgeous Japanese setting with some weirdest and most creative looking enemies I've seen in a long time. Capcom really nailed that PS2 era weirdness with this game and I love them for it!

Death Stranding.

Crypt of the Necrodancer.