Oberlin Court and Gateway Park are two apartment buildings that are pretty new (like built within the past few years) that are on the periphery of downtown, so that would make them pretty close to nightlife/restaurants, etc...while also having a good number of young professionals.
Oberlin Court is where Oberlin Road meets Wade Avenue, near Cameron Village.
Gateway Park is near the Boylan Heights area, where Lake Wheeler Rd meets Saunders.
Another that should be opening up soon (if not already) would be Carlton Place, nearby City Market/Moore Square Art District.