One actor I really enjoy is
Harvey Keitel . I would say he is of the same caliber as Robert Dinero. He actually played against Dinero in
Taxi Driver as the pimp. He gave tour-de-force performances in
Reservoir Dogs (also starring Steve Buscemi who was mentioned in this thread) and
Bad Leutenant . A bit of trivia, Harveys' character in
Reservoir Dogs "Mr. Black", also makes a short cameo in
Pulp Fiction (both films directed and written by Quentin Tarrantino).
City of Industry is also good.
One word of warning, most of his characters tend to be violent, and so are the films not too surprisingly.
Boosch