Hollow Knight - Best metroidvania game ever made! The art is all hand drawn and fantastic. There are over 40 bosses. The game just goes on and on and on. And I mean that in a good way. Any other developer would have split it up into two games. There's that much content in it. The platforming and combat is excellent as well. Later levels rival Super Meat Boy in their platforming shenanigans.
Into the Breach - A tactical game ala Advance Wars, or Fire Emblem. Except you are fighting giant bugs, and piloting a team a 3 mechs. This is grid based combat at it's absolute best! The rogue-like elements make it endlessly replayable. There are several teams of mechs as well as different pilots to try out. Each mech team has a theme, like fire, smoke, or throwing bugs. The game is perfect for the Switch, because a single game lasts only about 2-3 hours. The challenge is to beat the game with each mech team.
Stardew Valley - A fantastic farming sim, fishing sim, life sim, and action dungeon crawler. This game combines the best elements of minecraft, animal crossing, and harvest moon.
Enter the Gungeon - Take it away Dunkey!