Lately, I turned good at Scout.
There was a trick thou, the way I used to aim, what to focus and, of course, pratice, but now I know how to play it, I see why people enjoy it.
Engineer is still my most played class, I blame all these 30 min. long Dustbowl matches you spend swinging your wrench and yawning. Mini-Sentry plus widowmaker can be fun thou. My theory is engineer have fun by stealing it from the enemy team. It's the ragequit class for me.
Heavy still my best class, but got to a point I simply find it to... boring? Easy? I should try shotgun heavy someday just for the lulz out of it.
But I will always remember fondly the days of derping around with 225 HP backburner Pyro. To be young, and innocent...