Best Hamburger in Philly? (Anywhere?)

We tried this new place last night, and it was great. The chef had won a hamburger contest in Philly last summer, so I had to have the winner. Superb! It is called the Pork Roll Burger: homemade beef patty, slice of pork roll, Cooper American cheese, sunny-side up egg (the version in the contest had a quail egg), sriracha mayo, and a Martin's potato roll. Blue Duck is famous already for its duck fries, which were also great. The place is named for a line in the film Billy Madison, which can easily be found by Googling Billy Madison and blue duck. This BYOB also has some gourmet dishes at reasonable prices, such as a nice duck pot pie, and some good fish dishes.