I really like pins that reward good play and punish a bad shot instantly, Bally Eight Ball is my favorite for that. Good shots will keep the ball going for a long time, but randomly flipping the ball often/always results in a swift drain.
I hate pins and quickly sell ones that punish well made shots/play. If the ball normally drains from me making a required shot what is the point? That is just a badly designed pin. Flash Gordon came close to giving me this feeling, I could normally get decent ball times, but only by shooting for safe shots, like the spinners to keep the ball in the upper playfield. Shooting for the lower playfield targets pretty much guaranteed a ball was doing to go somewhere random even if I hit one of the necessary targets (often because the ball would end up bouncing into the pop bumpers).
Flash Gordon looked great in the lineup, but it did not last long in my collection. I just did not find much joy in playing it, a good game was more by chance than skill. The best I could hope to do was earn an extra ball at the start of play and than hope for the best with the targets after the extra ball was earned.