Williamsburg birthday dinner
I love 1 or 8 but don't think they take reservations. If the OP can do an early dinner, should be OK to walk in.
A casual option is Rye, which I've always had great experiences with. El Almacen is my go-to Argentinian steakhouse place. Sometimes a bit crowded and noisy, but a party of 2 can usually get seated within 30 minutes and the wait isn't bad if you enjoy a sangria at the bar.
557 Driggs Ave, Brooklyn, NY 11211
247 S 1st St, Brooklyn, NY 11211
Hip, quality, reservations, and birthday special: Dressler. Old school Italian: Frost (not hip but more "early years' hood"). And then there is always Peter Luger.
149 Broadway, Brooklyn, NY 11211
Peter Luger Steak House
178 Broadway, Brooklyn, NY 11211
193 Frost St, Brooklyn, NY 11211