I'm not sure I have a least favorite, but I can say that I hate the END of every season. I hate the end of Winter, because it seems to last forever. I hate the end of Spring because it's not quite time to go to the beach yet. I hate the end of Summer, because I've had enough of the heat. I hate the end of Autumn...hmm...maybe I don't hate that LOL
When it's Winter, I want it to be Summer. When it's Summer, I want it to be Winter. They have their own positives and negatives, but if I have to choose which one I dislike more, I would say Winter.
Summer. In Texas, we're gonna have two years in a row with record-breaking highs of close to 100f for almost 2 months straight. Not looking forward to it, especially since my AC doesn't really work that well in the summer. It's already averaging 90 right now and it's struggling.
Definitely summer, I live in Missouri and it gets terribly humid and hot during the summertime. Plus I work in a non climate controlled factory so it's hotter inside my work than it is outside. :S I like the other three seasons though, especially Fall and Winter! Spring used to be my favorite, but we hardly ever get a spring here. Thought this year we actually did get somewhat of a spring.
I would probably argue spring is my least favorite. Nothing like a bunch of pollen to ruin your sinuses and make you sick. ;( Summer would probably be a close second though, if only for the heat and humidity.