Good restaurant downtown for a date on NYE?

Just got back from a deployment, and the first time ill be seeing my girlfriend will be new years eve in Chicago. She's not 21 yet so I can't go to most of the big parties, and I'm trying to avoid most concerts as everything good is sold out.

Essentially, what's a nice restaurant downtown I could try and reserve last minute? And any other attractions/sites I could go afterwards downtown? Any help is appreciated as I haven't been in Chicago in years!