When I fly an La7 from a field being horded, and they cry it's unfair. Pitty.
I love the La-7 when it's low, easy free perks

I think the plane I get the most complaints out of is my P-51. I guess it's because people rarely see someone fly it as aggressively as I do. I'll take it up, and turn till the enemy is on my six, more than a few times, someone will get careless and let me go over the top (the P-51's flaps feel almost designed for that) and I'll come down for an easy kill. That's what usually gets people mad.
Or when I make a lucky 600 yard out Tater shot from my P-39.