Really Good Italian for Birthday
As always, kobe has made two good suggestions. Here are my views on them which I hope will be helpful.
While most people think of Hearth as Italian, I found the food to be more New American with a tilt towards Italian in some dishes. On the other hand, L'Impero is definitely Italian of the contemporary variety. The food at both is very good, but I would have to give a nod slight more in favor of L'Impero. That might be partially because I was so utterly blown away by the insanely delicious polenta and mushrooms!
Another factor might be the ambiance. Hearth is a big place, and the front room where we sat was kind of on the noisy side because that's where all the larger parties are seated. As for the decor, I think of it as "early warehouse," i.e., rough minimalism, though it is saved by proper lighting which helps give the space a warmer feel. L'Impero has elegant contemporary decor and soft lighting that gives the space romantic ambiance. And if you happen to be going there during the warm weather months, the small, charming outdoor patio facing the park is truly romantic.
Just one note about A Voce. We really liked the food but, as I've mentioned before, the thing that has kept us from going back is that when the dining room filled up, the noise level was so insanely high that it was impossible to carry on a civilized conversation.
Wherever you decide to go, I wish you a "Happy Birthday!" and hope you have a wonderful time.