It's been awhile since I lived in Atlanta, but Blue Pointe in Buckhead used to have an absolutely amazing selection of cold water oysters. For steaks (and a nice bottle of wine), Chops was one of my favorites.

for years the top rated restaurant in Atlanta has been Bachanalia and for seafood you might try Kyma - it is a sister restaurant to Blue Point recommended above but it focuses on Greek/Mediterranean styles as opposed to the more continental style of Blue Point.

Food first:

I live in Buckhead and eat out almost every night but not in Bickhead.  On the whole there is a difference between Bickhead and Midtown restaurants.  Buckhead is dominated by the larger corporate style restaurants and most of them are steakhouses (including Hal's, a locally owned Buckhead bueblood favorite). Midtown has mostly chef-driven restaurants with more interesting cuisines.  My preference keeps me away from larger restaurants, which is also typically the Buckhead restaurant since this is where most most of the tourists and conventioneers go.  So I go to Midtown the vast majority of the times I go out.  The exception to Buckhead is Local 3 (my current favorite and is more like a Midtown restaurant) but it isn't near the central Buckhead.

Midtown has 3 areas: Virginia-Highland which is the name of a neighborhood and an intersection where this area first became a entertainment/dining area and is on the east side.  An area in the center of Midtown, which is along Peachtree St. (yes, there are 56 streets named Peachtree here) and Westside which is primarily along Howell Mill Road at 14th Street.  

I don't know what type of food or atmosphere you like so I can't make any recommendations but you are welcome to PM me withndetails and I will send you names and descriptions.

Where to stay:

You need to be centrally located with ease of access.  Most people say they find Midtown difficult to navigate so I suggest you stay in Buckhead.  Either way, Atlanta is a car town so you need to rent a car and definitely bring a GPS device if you don't have one on your phone.  Remember Atlanta is not NY, the cabs are roaming.  You will have to call a cab whenever you need one. The larger hotels will typically have a couple lined up waiting but once out, you will need to call, probably Buckhead Cab Co.  It is the one I have used when I've had too much to drink or need to get to the airport.

Again, you're welcome to PM me if you have more questions.

Z

I'm partial to Buckhead.  Good restaurants in Buckhead.  I'd disagree that Midtown has better "chef run" restaurants than Buckhead.   There are tons if chef run spots in Buckhead.
Restaurants I'd hit rec to you (let me know your tastes and I can recommend more)

Aria - best restaurant in Buckhead
Pricci - good Italian
Hal's - good hangout spot.  I like the gumbo there. Good looking wait staff.  I swear they purposely rub their tits on my back at the bar.
Tavern at Phipps - near all of the hotels.  Stick with bar type food and basics.  Upscale 30-40 pickup joint.
Fillenis/LaFonda - good quick pizza/or tacos.

I personally think Bluepointe has seen better days.

Kyma is good but $$$$.  I do like the apps at the bar.  

Bistro Niko has a good vibe/looks great.  The food is good but I'd personally go to Anis for French food. Nice patio at Anis.  If you are solo I'd hit up B Niko.