For me, it's Spring. After a long hibernation, I can't wait to get out. Fall comes in a close second.
Here in the South, we don't really have but two seasons. Fall and Spring are so short or non existent you usually miss them. Winters are very mild normally, so I like it. Summers are brutal.
I'm much more active outside in the spring. Getting the lawn ready, planting flowers, cleaning the porch, etc.
Activeity never stops.
Probably fall. It's actually going to be almost 90 here tomorrow, so still feels like summer in some ways. Fall here tends to be kinda warm, but cooler at night, and because the sun is lower, it feels less hot than during the summer even if the temps are similar. I do a lot of bike riding in the fall.
I tend to do more in "spring", which in Florida means late February, March, and early April. I get my garden started, and get more hiking in.
When am I NOT busy. Lol!
Spring. After our cold winters here, I always look forward to the warm weather, and the tree and flowers blooming. It's nice to get out after being cooped up for most of the winter.
I really do love Autumn. It gets me in the mood to prepare for all of the upcoming holidays.