Fall, most favorite. Cool enough to adventure outside, warm enough to not wear arctic weather clothing to meet minimum requirements for cold weather survival. Weather is varied, cool, breezy, rainy, snowy. Every day is interesting, every day is nice. Not too hot, not too cold.
Spring, second favorite. Weather is rainy, snow melts, still cool during nights, some warmth from the sun during the day. Perfect for adventuring and camping in some places, though snow-melt does make things rather wet.
Winter, next favorite, snow opens up Skiing, Snowboarding, free air conditioned outdoor Strongman training, and sitting inside near a window with a crackling fireplace, steaming mocha on the table and a good book in hand.
Summer, least favorite, but still enjoyable so long as it doesn't get too warm. Camping, hiking, hunting, trail running, swimming, climbing. No fireplace though.
My general saying goes, "In cold weather, you can always put on another sweater. In hot weather, there's only so many clothes you can take off." Now, know for folks here who admire bodies, that's probably the opposite of what you want to do or see; but me--I'm an Alaskan living in Texas, so, physiques aside, I'm biased against hot weather. Not much of a beach/party person either. So it's off to the alpine with me!