Lurker who just happens to be a Baltimoron here, and so I thought I’d contribute.
There’s one place in the Baltimore area that puts out BBQ that’s at least as good as any place in the south I’ve been, and it’s called "The Corner Stable". It’s got its own website at http://www.cornerstable.com.
I go there infrequently, because I can’t go there without eating myself sick. The appetizers are great, my favorite being the beer-battered cheddar cheese nuggets, and the salads are delicious, and I believe the dressings are homemade – at any rate I’ve never had a pepper parmesan dressing anywhere else that even compared.
The ribs are incredible. I’ve only once had even a scrap of fat on them, and yet they’re so tender and moist that you can peel them off the bone with a fork. The ribs are served in a plastic basket with the fries right in with them, which is good if you like bbq sauce on your fries (I do). The fries by themselves are tasty, but tend slightly towards being overcooked. Other sides include baked beans (great) and coleslaw. As for dessert, the Cheesecake Factory provides the cheesecakes that make up a significant portion of the dessert menu.
Incidentally, Corner Stable also does some of the best crabcakes in Baltimore too.
There’s another ribs joint in the Baltimore Area, "Razorbacks" up in Towson. I’ve only been to Razorbacks on occasion, and they’re honestly not southern style ribs. What sets Razorbacks apart is the different bbq sauces they put on them. In addition to the standard, they’ve got Louisian Burbon, Spicy Texas, a Carribean style mango based sauce. Razorbacks is a raw bar and they’ve got several shellfish based appetizers, as well as oyster shooters, and though I’m not much of a drinker, some of the people I go there with speak very highly of their mixed drinks, especially margaritas.