Autumn because it is so beautiful and peaceful. You can wear a jacket and be warm or not and be cool. The weather is perfect. There aren't many insects. I just love it. Also, I live in an area with a lot of forests, so it's even better.
Fall because of the colors the leaves turn in the fall, It is cool but not cold, the smell of moist, dead, leaves. But it is also dismal because it announces the coming of winter and because where I live, fall only last from two days to one month