Summer all the way. Early Summer (Spring) too.
I much prefer having a summers day pass by and regretting it going to waste than a winters day where you are stuck inside because it is miserable outside.
I absolutely prefer being warm (even too warm) than cold.
I love being able to jump into a river, lake or the ocean to cool off, and possibly make a day of it with various water sports/activities.
I like taking cold showers... and stepping out into a warm room/house... with all the windows open!
The ability to wear less clothing/footwear and feel more comfortable is a huge plus! Flipflops forever!
A summer day just opens more choices and options for me to spend my day when compared with a winter day, considering the activities I enjoy.
Oh, and more hours of daylight just put me in a better all around mood.
Don't get me wrong, I do love snow. But where I grew up there was a decent chance you could still be skiing/snowboarding into late April or May, allowing for spring skiing where you could get away with wearing pants and a t-shirt in 60ish degree weather (16 Celsius). Oh and possibly a hellish sunburn.