Hard to even decide if he's my favorite, but I'll go with Sergio Leone and put The Good, The Bad, and The Ugly as my favorite film by him.
The Dark Knight
For some reason I really like Mark Pellington's directing style, however he's only directed a couple movies, but I really like the 2 he did: Arlington Road and Mothman Prophecies.
Kill Bill Vol 1
Paul Thomas Anderson
Joel and Ethan Coen
Guillermo Del Toro
In no order.
Too many to name. Hitchcock. Ridley Scott. Coens. And of course Martin.
And my list would not be complete without John Hughes. That man never got enough props for the awesome films he gave us.
I think Ang Lee should be up there. He's shown a ton of versatility as a director.
I'm gonna throw in John McTiernan too for his job in directing two of my favorite action movies ever with Die Hard and Predator.
He growls as he storms the country,
A villain big and bold.
And the trees all shake and quiver and quake,
As he robs them of their gold.
Scorsese and Nolan
Del Toro with Pan's Labyrinth, but it's very close with Tarantino's Inglorious Basterds and Kill Bill Vol 1.
Rob Zombie is pretty great
Joss Wheadon been A fan of his sin e Buffy,Angel and Firefly.Favorite Movies The AVENGERS and Serenity are the obvious choices but I really liked The Cabin in the Woods.