Definately the open mouthed chewing can irritate the life out of me.
I also really really struggle with idling vehicles that for no reason are parked and have their engines running omg I have wanted to throw rocks at their cars.
People that seem to rub their faces comstantly like a stimming process.
Consistant clearing of the throat from people or non stop sniffing.
Just repetitive actions of all sorts that dont seem to have an outcome to the action. hahahaha