With such a broad request, best to go to opentable dotcom and check on the dates and times your interested in. See what's available. Decide on the cuisine and nabe, then do a search on this board for the comments of other hounds before making reservations. Bon apitite!
On the UES I like davidburke & donatella (fancy) and Fig & Olive (casual). Midtown: My favorite place: Vice Versa (their sister restaurant a few blocks away is Etcetera Etcetera.) Also in Midtown is the popular Marseille(casual) French in Midtown? Rene Pujol.