Atlanta for two days and want to taste the cuisine
"Atlanta" is geographically huge...it can take 2 hours to drive from one end to the other. Which W are you staying in? I believe there are 3. Will you have a car? How far are you willing to drive? Any cuisine or price preferences/restrictions?
You might want to start by doing a search of the many existing threads, such as:
If you get tired of venturing out, I like Spice Market right there in your hotel, though it doesn't get a lot of reviews on Chowhound. Fun atmosphere if you've got a group returning from a wedding event and want to hang in the hotel. Otherwise, Carolinadawg has given you the best options.
Some lunch thoughts: 6 Feet Under on 11th street or Vortex a few blocks down Peachtree
Breakfast: West Egg at 14th and Howell Mill or Flying Biscuit at 10th and Piedmont