Husky99
Just so I have some perspective, what age range are you and your wife? That would help a lot as to what you might enjoy.
Like others have said, the aquarium is cool, but in the end it is just an aquarium (but one of the better ones)
The MLK museum is truly unique, something you wouldn't be able to experience anywhere else. I use to live near freedom pkwy, so even if you just wanted to drive its awesome for sight seeing as well, bc Dr Kings actual birth home and church (Ebenezer Babtist) are easily accessible and restored very nicely as well.
The one great thing about Atl, is the restaurants, there's so much variety as well as being top notch. If your looking for something special just to Atlanta that you wouldn't find else where my suggestions would be:
Gladys Knights Chicken & Waffles
Vortex (burger joint) 2 locations, I'd recommend the original in Little Five points
Two Urban Licks (a pretty trendy spot, I'd put money on that your wife would enjoy)
There's some great comedy clubs if you were looking to stay busy towards the night as well
Someone had mentioned Stone Mountain, which is a must see (especially over the summer, when they do the light shows), also there's a stone carving much like Mt Rushmore, actually bigger that I never knew about until I went. Eventhough it's of confederate generals (being a Yankee myself) it was still a sight to see, and easy to do so using one of those cable trolleys that brings you to the top
The botanical gardens are cool as well, and probably something your wife would enjoy
Cheetahs, lol....ya you'd enjoy, not so sure about the Ms though lol i must say though for a strip club, cheetahs is very high class. Just putting it out there but if you really wanted to get a "true" sense of an Atl strip club check out Majic City, I was never aware women were able to some of the things I saw, lol....but I digress
All in all, there's a bunch to do and see here, especially in the summer where IMO the best part of living in the area is the festivals that go on almost every weekend in a different part of the city.
If you have kids with you, ya can't go wrong with Six Flags too. Hope that helped.