Defintely Ripert, Bouley, Batali, and Boulud.
Gabrielle Hamilton of Prune.
Masa Takayama.
Both Dan Barber and Anita Lo are amazingly talented.
(although i haven't eaten at Kurt Gutenbrunner's Wallse, wd-50, Per Se, or Cafe Grey)
i'm surprised no one's mentioned the arepa lady.