My favourite game of all time is
Chicory: A Colorful Tale, it's such a love letter to artists and it means so much to me.
Wandersong, a game by the same dev, is also extremely important to me, to the point that i ended up using the name Bard because of it. i recommend both heavily if you want some new indie games to play.
However before i played either of those, LittleBigPlanet 2 was my #1 game. LBP is no doubt the most important series in my life for MANYYYY reasons, it fundamentally shaped who I am and is why I do what I do. It's been in my life as long as I remember. To be honest, I think it just transcends being a favourite game at this point, it is so much more to me and if I were to explain why, i would have to write like a 1000 page essay haha.