Definitely David Lynch and David Cronenberg. My two favorite directors in the whole world.
In keeping with the theme of great directors with low output, I submit Terrence Malick, who has directed all of six films in the last forty years. And no Oscar.
But Herzog directs English films as well, such as Grizzly Man, Rescue Dawn, and 2009’s Bad Lieutenant: Port of Call New Orleans.
Until Encounters at the End of the World (in the documentary category), none of his films had even been nominated for an Oscar.
Oh, I know it’s theoretically possible that they could pull a Forman or Bertolucci, but the type of films they currently make (in English) makes it unlikely. I think Herzog in particular has a better chance of winning a doc Oscar over a director one.
I’m all kinds of terrible with names…but isn’t there a guy who has only directed three movies, but gotten nominated for all three?
Would he be a candidate?
Well, it depends, but since I consider all three (Billy Elliot, The Hours, The Reader) unbearable in their own unique way, I would humbly say No.
About five too many, to my way of thinking. Not a fan. 
Paul Thomas Anderson, but he’s young enough that he’ll get one eventually – just like what they used to say about Spielberg.
Oh, and Spike Jonze.
Oh come on. Bring it. Spike Lee.
I think this is the answer. I forgot Spike! Not sure he’ll get one because he likes to pick fights and second guess Oscar selections.
George Lucas… duh!
Sam Raimi. My favorite living director, after David Lynch. (and just ahead of Fincher and Tarantino)