A lot depends on your lodging preferences and price range. You can stay right downtown at the Hotel Roanoke and be within walking distance of some great clubs, such as Metro and Corned Beef & Co., and a variety of restaurants. But, the rates are a bit high. You could also stay near Valley View Mall at the Hyatt Place, Comfort Inn or Mainstay Suites and be within walking distance of tons of shopping and chain restaurants. My friend owns the Red Palace Chinese buffet and I quite like it. It is located right next to the Hyatt Place. Buffalo Wild Wings (B Dubs) is located in the mall. Great for a drink or two.
If I were to pick the best food in Roanoke, which is a highly subjective endeavor, I'd probably go with Carlos Brazilian International Cuisine. Here's their website: http://www.carlosbrazilian.com/
Enjoy your stay and the beautiful Roanoke Valley.