Carson Street Deli is a great South Side business.
For over a year now, the owner has been running a Wednesday night beer tasting. This is the place to be to learn about every new brewery that gets distributed in Pittsburgh and learn to like a few new types of beer. Don't miss the annual stout float tasting! They also have a constantly rotating tap selection. At least one tap is always devoted to East End, and this is the place on the South Side to get East End growlers filled. If you don't have a growler, they have good prices on a great variety of choose-your-own six-packs.
Aside from beer and Wednesday nights, Carson Street Deli has always-dependable sandwiches. Large but no grease, so it's one of the healthiest lunch options if you're on the South Side. If you get a sandwich with deli meats on Breadworks bread (i.e. the Godfather), you won't be disappointed.
As an added bonus, this is one of the cleanest and well-lit "bars" on the South Side - a place you can go with your Mom or new significant other.