Harmensz van Rijn Rembrandt
Rembrandt is considered to be one of the best painters of all time. His subjects are mostly portraits and scenes. His interest was mostly in the expressions of his subjects. Their body language and facial expressions.
He refused to paint flattering portraits like so many of his peers. He wasn't looking to impress people wealthy enough to commission portrait painters. He not only painted the rich but the poor and sickly. Faces are painted with wrinkles and flaws capturing what the person actually looked like. But the paintings bring out even more of the person's personality. Much like the work of Lucian Freud.