Attman's is the best deli in Baltimore, and quite possibly the world (this is only possibly an overstatement). Located at 1019 Lombard Street, (between President and S. Central Avenue), it's a tiny little place that serves pastrami like you would not believe. If you want further proof of this, just look at the street sign that marks that section of Lombard as Corned Beef Row - there used to be several delis in the area, but now it's pretty much just Attman's.
The place is always packed, so be prepared to stand in line for a little bit before you get your food. And be warned: you should know what you want before they ask you what you want. They do not take kindly to indecisive people.
They've got everything a good deli should have; creamed herring, pastrami, corned beef, black bread, potato pancakes, bagels and lox, pickled onions, and rice pudding. Plus plenty of other tasty treats. My favorites are the Jessica Special (corned beef and turkey covered in Russian dressing on rye), and, of course, the Rueben. They also serve Kosher all beef franks on big thick rolls with lots of mustard and onions (the way it ought to be!).
They sell juice, soda, and various beers for your drinking pleasure. Probably coffee and tea as well, but I've never checked. I recommend Stewart's Orange N' Cream Soda or Dr. Brown's Root Beer.
Eating there is probably similiar to shooting up heroin, but slightly cheaper. Just as good a high, and damn near as addictive, though.
You can either take the food with you, or eat in the Kibitz Room, which is a nice little area with tables, most of them occupied by old Jewish men (always a good sign for a deli).
Call them (410-563-2666) for operating hours.