For me they are in order; Mario Batali, Thomas Keller and Ferran Adria. I'm glad to say that I've actually met two of them.
I have the greatest respect for Julia Child but I think her biggest contribution was teaching Americans what to eat rather than just how to cook it. That was an eye opener in the US.
Other candidates: Keith Floyd, Paul Proudhomme, Alice Waters, Fergus Henderson, Gabriel Hamilton.
You won't get past the doorman list: Rachael Ray, Sandra Lee, Bobby Flay, Robert Irvine and all time loser David Ruggerio.