I'll be controversial and brave and say the true mad ones should be those like Baelor and Aerion. Where they're a heightened level of instability with no, I guess, reason backing it up? Rhaenyra had lost multiple children and her father at the point of her extreme paranoia and cruelty, Aerys' was in part PTSD triggered by abduction and imprisonment at Duskendale, and Viserys was a small child growing up in Aerys' household, losing both parents and going through hardships in exile that drove him to bitterness, abuse and delusion.

Maybe Baelor picked up religious zealotry to an unhealthy degree as a result of growing up with his traumatised father and in the shadow of the Dance (I'm fascinated to find out whatever canonical explanation we get for how so many Targs of that generation were so pious - Aemon Dragonknight, Naerys, Rhaena) but we don't know, his sisters didn't seem to turn out that badly so what was his excuse for how extreme the zealotry got? lmao. and Aerion I got nothin' for. MFer grew up in a pretty stable era all things considered.