While autumn is my favorite IRL, I chose winter. I love the camper igloos, the crunching sound it makes to walk in the snow, the way the hourly music changes with jingle bells, the lights on the cedar trees and the way the snow looks on holly bushes and bridges, Toy Day, New Year's Eve (which I do not enjoy IRL, actually), and the magical feeling when the town gets the first snow flurries of the season. I don't particularly enjoy making snowmen, but I do enjoy the resulting snowflakes, and collecting ice furniture from the Snow Mam.
The only season in ACNL I don't really like is summer--as some meme said, it turns into Animal Crossing: Cicada Hell.
You would think that living in Aus I would love the snow but winter is my least favourite in game season. The snow gets annoying after the first month and it seems to last forever.
Spring is my favourite cause everything is like brand new and much brighter and happier