Well, actually the City Tavern in Old City has been around longer, but since McGillin's has had its liquor license continuously since 1860 it's technically the oldest pub.
Anyway, it's located on a slightly off the beaten path street between Chestnut and Sansom so finding it might be the first challenge. Once you do find it, you'll notice the large bar on the right-hand side when you walk in and then a bunch of tables laid out almost like picnic benches throughout the rest of the bar. Being in the heart of Center City, most of the clientele are city workers and business types.
Try the two house beers, McGillin's Ale and McGillin's Lager. Neither is exceptional, but at least they are unique.
Dress Code: Come as you are.
McGillins Olde Ale House has got to be one of the coolest old pubs in Philadelphia, in the country for that matter! This place was established in 1860, which by American standards is incredibly old for a local business of any kind. McGillins has been restored to all its historical glory and has lovely old world charm. It's got a gorgeous carved hardwood bar and other nostaglic decor. This place is nationally famous and has been visited by many celebrities. If you have to pick one bar to visit in Philly, McGillins is it! I prefer McGillian's during the day when it is not as crowded and the music is more low-key.
Local microbrews on tap. Limited bar menu- American food.
Dress Code: Clean casual.
$4 pitchers of beer, and the best chicken wings in Philly. And, the wings are $0.15 each, but all of this is only on Tuesday nites.
It is the oldest bar in Philly, and it's got good atmosphere. Upstairs isn't as big as downstairs, but it's better place to find a place to sit if you arrive later. Downstairs has TV's set up around which is good for game nites.
There's nothing special about the beer, because it's the wings. They are so good. They are MEATY!! They are covered in just the perfect amt. of wing sauce as well. Also, there's no problem in asking for more celery and blue cheese if you want it.
Dress Code: Don't wear anything too extravagant, but people do tend to get doll'ed up a bit. I generally don't wear anything that I don't want to get wing sauce on.