A famous artists who paints facial expression?

i need to find an artist (or several if possible) that concentrate on painting faces, or more specifically; different facial expressions. though portrait artists would be great too... so i'm open to suggestion. i'm looking for any type of more conventional artist, though photographers and the like would be good too. :]A famous artists who paints facial expression?
Rembrandt certainly made studies of faces like that, also Leonardo da Vinci. Various artists went to Bethlehem Hospital (Bedlam) and drew the inmates. Hogarth would be good to look at, especially series of prints such as the Rake's Progress. The trouble with portraits is that the people posing can't keep a distorted expression for very long, which is why they are normally painted serious or only slightly smiling. Ooh - another I've just thought of - Melancholia by Durer.