I was not impressed with Gilt my last visit but it's an improvement over Le Cirque IMO. This board has a lot of EMP fans. Between the two I suggest you go to EMP. If you have not dined at Daniel I suggest you consider going there for your birthday. It's one of my favorites. I also suggest you consider Jean George's, Le Bernadin or Del Posto.
1 Central Park W, New York, NY 10023
85 10th Avenue, New York, NY 10011
151 East 58th Street, New York, NY 10022
No comparison (IMO), EMP by a mile. And I could recommend other places but you hit on one of the best right off the bat but FWIW there is The Modern, Le Bernardin (if you love fish this is the place), Daniel, all are wonderful for their own reasons.
155 W. 51st St., New York, NY 10019