Voice of reason characters are almost always ignored. Here's some of my faves :
Mammy - Gone with the wind
Peter Boyle in Taxi Driver - advises Travis Bickle to be more outgoing and sociable...
Mum from At Close Range (1986) : is no longer fooled by the charms of psycho dad Christopher Walken. Ordering him to get out of her home the minute she sees him again.
and YOU?