If you're a frequent Delta traveller there's a better than even money chance you regularly pass through Hartsfield in Atlanta. If you're a Diamond Medallion/Sky Club member, American Express Platinum Card holder, or willing to shell out the $25/$50, then you've probably had this experience: walk into the SkyClub to find a mile long line at the bar and not a seat anywhere in sight.
My preference is definitely for the self-service Sky Club (LAX has a nice one). Unfortunately, there are none at Hartsfield (that I know of). There are, however, a couple off the beaten path of the concourse. One is on the A Concourse. As soon as you come up from the "travel loft," head towards the Chili's upstairs. It's a marked improvement from the club down near 17. The other is out in the E concourse. Keep walking past the first Sky Club like you're going to gates E14-E17; it will materialize on the right. They may not be ideal if pressed for time, otherwise they are worth a stopover.