Autumn/Fall is my favorite season in both real life and Animal Crossing. I love the colors of the trees and grass during those months, I love the holidays (Halloween, Thanksgiving), and my birthday is in Autumn too! It's also right before my second favorite season, Winter. It's just a good time all around.
Fall. I love Halloween and the colors in november. Summer used to be my favorite for all the money making opportunities, but now that New Leaf has the island, i definitely prefer fall.
It would probably have to be summer, even though that's a bit boring. I love the colour of the trees in Fall, but the grass doesn't look so great. I love the atmosphere of Winter, but the snow doesn't always look that nice, even though the snow on the bushes and buildings is really adorable. And I don't actually like Spring all that much.
i love spring for the cherry blossoms and the return of green <3 but I like summer a lot too, it's hard to choose. I don't mind fall or winter, but the color scheme gets old fast as does the snow. by January I'm missing the green grass already ;-;
I like Winter. Winter time in Animal Crossing is so comfy. I like it when there's a heavy snowfall or seeing the aurora on a clear winter evening. But the transition from Fall to Winter is the best, the tree leaves getting dull and the snowstorm that officially marks the season change is so nice.
On contrast, I dislike Summer and the thunderstorms associated with that season.
I used to think spring was my favorite in-game season, but that has changed to fall. Mostly due to seeing my town in all the beautiful colours last fall.