NewYorkMag.com lists 73 and Menupages.com lists 185 Italian restaurants in Midtown.
In addition to Blumie's questions about location and budget, here are some more that will help us help you narrow it down:
Northern or Southern Italian?
How many people will your party be?
By "lively" do you mean you're looking for a hip scene, a place where you can get a little loud on wine and not bother anyone, or something else?