Decatur could work...Brickstore, Leon's
Here's a suggestion which pushes your request a bit...
I went to Holeman and Finch the other night....really enjoyed the food and fun trying things.
Our group of 7 got there at 5 p.m. to ensure a table. No reservations there. For lots of food and a couple of bottles of wine, we only spent about $60/person. It might go over your budget a bit but it was fun. You have to have adventurous eaters. If you have guys who want a burger or a steak it's probably not the best place.
Definitely agree with The Brick Store or Leon's. Also The Porter in L5P (I'm still happily recalling the sting of the buffalo shrimp po boy from this weekend). If you wanted to go even more casual, I guess Farm Burger, Grindhouse. or Fox Bros would qualify. Or Bocado for more upscale. Or brewpub- 5 Seasons or the Wrecking Bar.
Eclipse di Luna is also a go-to place for us, though they've finally raised their prices after many years (it's still a pretty good deal, though). The Tree House in Peachtree Hills does good (if not adventurous) food and has a great patio if the weather is nice (wouldn't go otherwise).
I just generally am not excited about The Vortex b/c I've gotten used to not having to do secondhand smoke with a meal.
Another idea- we were really impressed by the food at STG Trattoria, even though the pace of getting it out of the kitchen was glacial when we went.
I love Holeman, but I rcburli's right about it being a bigger tab. I also tend to gut-bomb myself by indulging in too many rich things when there.