My favourite game. That's a difficult choice. Rimworld would be a close second, but I have to give this 'award' to Planet Coaster.
The amount of creativity that it evoked in me was insane! Sure, it's a fun game, but I love that it made me feel creative. It totally did steal a lot of my time, but it was worth every second :)
That's like @mwoodall. His favorite was a Farm Simulator. There's nothing like being able to build something from scratch and see it go.