I think I like early fall the best. I love warm temperatures, warm not hot. Fall is still warm enough for this perpetually cold person to be comfortable without being overbearingly hot.
Plus fall has the added bonus of all the leaves turning beautiful colors. I loved helping my parents rake them and then getting to jump in each pile once before my dad neatened them up to burn. As I grew older, he had to bag them instead of burning because they passed a law against outdoor burning in my home state, but the memory of that smell of burning leaves left an impression on me. Where I live now as an adult, they still allow leaf burning as long as the weather hasn’t been dry, so I get to relive those memories through that smell.