It feels a bit like cheating to have this here; the variety of level design possibilities on offer is something that just can't be matched elsewhere.
1
Sonic Mania
What sticks out about Sonic level design is the depth to it. Other platformers might hide a small room or piece of level off on the side for the sake of containing collectibles; in Sonic there is no main path. Each act is a branching, multi-layered maze, and only by retrying and revisiting will you find the quickest route through them. It helps also that each zone is such a distinct idea, with memorable music.
2
Donkey Kong Country: Tropical Freeze
3
Celeste
4
Super Mario Odyssey
5
Rayman Legends
6
Ori and the Blind Forest
7
Yooka-Laylee and the Impossible Lair
This game feels like a potluck of borrowed ideas: a lot of DKC here, some Yoshi's Island there, Rayman Legends on the side. It maybe never becomes more than the sum of its parts, but Playtonix deserves credit for what they have brought to the table: a very clever overworld with altered versions of levels, and a fairly flexible approach to difficulty.