Andrew Dominik. Three films and all three are absolutely outstanding. Yet, almost no Oscar nominations (and none for him personally), total indifference from audiences and even the critics aren't fully on his side - The Assassination of Jesse James couldn't even manage 80% on RT, although it seems to be getting more and more acknowledged as one of the best films of the 2000s.
Lynne Ramsay. While I'm not enthusiastic about Morvern Callar, her debut Ratcatcher is a hell of a film, beautifully turning the grim kitchen sink drama on its head, and We Need to Talk About Kevin is an absolute stunner in nearly every respect, one of the most remarkable films of the past few years. Once again, no major prizes, not even from Cannes, and not enough attention from critics.