In no particular order, and without adjusting for recency bias:

Single player

• Hollow Knight
• Undertale
• Outer Wilds

Multiplayer

• The Finals
• Awesomenauts*
• YOMI Hustle

* Right now the game is in a weird state where the original company who owned it went backrupt, and the game is in the process of being revived by a different company. In the meantime, the already low player count got lower. On top of that, there’s two versions of the game: an old version that used Steam matchmaking (as the matchmaking server went down when the game original closed); and what had been the current patch, being accessible on a beta branch, which currently has issues making it hard to actaully play a match.