I generally prefer spring, where it's often just the right temperature. Warm but not hot and often breezy.
I like some warmer summer days but past about 80 F it becomes a bit too much. I do love summer nights though (no one had better post the Grease song). Spring nights tend to be on the cooler side, but summer nights often retain some warmth and are more like spring days but with the stars and moon shining instead of the sun. Makes you feel so alive and happy.
I both like and dislike having more free time in the summer. It's nice because well, FREE TIME, but it can be sad if you have no one to spend it with, or if each day feels aimless.