What's the Best Bar in Philadelphia?

Well, as I stated before, I tried out Friendly's Lounge at 8th and Washington after I learned from Foobooz that it was one of the top 50 bars in America. And it was OK. But I can't say with a clear conscience that it was the best bar in Philadelphia. So then I got to thinking, "Well, what is?" I do have to say somewhat proudly that w/o even needing to shill, all of the places that I do quizzos are damn good bars. But I will remove them from contention to be fair and balanced. (You are welcome to include them below.) What do we mean by best bar? I think we have to set ground rules and say that it is a bar first, restaurant 2nd. It can still have good food, but that can't be the main reason to go. I'm a big fan of some of the ones in my 'hood, such as Grace's, Doobie's, and Sidecar. I also love Nick's Roast Beef in South Philly and in Old City. Yeah, it's got food in the title, but I still think of it as a bar first. I like Bob and Barbara's, despite all the hipsters. But I think I gotta go with Oscar's. Cheap beer, strange old fashioned drinks, and damn good cheesesteaks. And best of all, a very diverse crowd at all times. You got students, lawyers, convicts, and quizmasters. And they pour a pretty good Guiness at a damn good price. You guys post your favorite spot, and then we'll take a vote, and see what the verdict is. What's your favorite bar in Philly?