Philly has immense historic significance for the USA, even more so possibly than Boston. This was the city where the declaration of independence and the constitution were both penned. The city was the meeting place of the Founding Fathers and several important battles were fought nearby.
Crime
Violent crime isn't particularly rampant in Philadelphia, however there is plenty of it to warrant for the kind of violence you'd expect from a GTA game. There were almost 16,000 occurrences of reported violent crimes in the city in 2014, with a total of 248 murders in the same year.
Robbery and aggravated assault are also pretty frequent, of course depending on which area of the city you are in. Philly isn't exactly known for gang activity, but there are quite a few active ones in open conflict with one another.
Philadelphia has also become a major economic center, with a bustling downtown business area and several HQs for Fortune 1000 companies. As such, white-collar crime is pretty high in the city, which seems to fit GTA's new direction, as dictated by Executives and Other Criminals and Further Adventures in Finance and Felony.
Recognition
It seems that the cities we evaluate in these articles fall into one of two categories: extremely iconic or not iconic at all, with no middle ground. Philadelphia decidedly falls into the first category, with countless historic sites and buildings of national importance.
The First Bank, Independence Hall, Elfreth's Alley, Congress Hall, the City Hall, The Washington Monument (not the white pillar, that's in D.C.) and the National Constitution Center are all within this city. Foreign players with merely an ounce of knowledge about American history will recognize countless landmarks in the city.
Potential Story
With the obvious historic significance of the city, the best venue for the story would be to go in the direction of having a criminal organisation the members of which have a flare for naming themselves after important figures of the Revolutionary War, taking control of notable landmarks as hideouts and working towards igniting a "new revolution". We mentioned a similar idea in the Boston article.
The player would either be with this group, or working against it. Seeing as Philly isn't famous for its gangs, the game could be rooted more in the white-collar crime aspect, with the protagonist(s) being corrupt officials or corporate figures with a hand in illegal activities.
Of course, its not like Los Angeles is particularly famous for bank robberies, so Rockstar could just go with a story not necessarily linked to the city itself, however when dealing with a setting as significant as Philly, it would be a bit of a waste.
Final Verdict:
A(++)
Pros: Great recognition, high enough crime rate, story potential.
Cons: Geography only okay-ish on its own, but perfect if Atlantic City is added.
The two pluses in the parenthesis are there denoting the score should the recommendation of adding Atlantic City as a second urban area be heeded. On its own, Philly would make for a pretty good GTA setting. Slap Atlantic City to it, plus the countryside in between and you have a perfect GTA setting.
Philly has many favorable assets in terms of becoming a map for GTA VI. Of course, the crime aspect could be more pronounced, but in its current state it is prevalent enough for the game's purposes.
Which city would you like us to look at next week?