in the game I'd have to say spring but I can't really judge since I got the game this past December. I just like not having to deal with snow people anymore. IRL it's winter.
I like all Animal Crossing seasons because no matter the weather, the game looks so pretty! <3 My favourite season would be summer because I like the sun. However, that said, I also LOVE when the snow falls and the music gets all twinkly!
Spring has so many bugs to keep, sell or display in the museum along with the sakura trees. It's just amazing to see in general. In winter, there's barely anything good to catch so it's hard to make bells excluding visiting the island, but the snowman games and creations are the pros of the winter theme