I think that, for the most part, Ruby Legs hit the nail on the head and there's not much I can add to it other than the following couple observations:

1) I totally agree with him about zoning reform and improving public transit. I believe that one of the things that's driving New York City is its excelent public transit. I know a couple people who have moved there (who could afford to, apparently) who named this as a major reason for the move. I've also met one or two people who moved here from New York (couldn't afford it, maybe?) who have complained about the inadequacy of Philadelphia's transit system. Same goes for walkability: bringing more retail to the city improves it, but putting that retail in big boxes surrounded by parking makes the city less appealing, IMO.

2) Speaking of affordability in NYC, property tax reform would be a top priority for me if I were mayor. In addition to help for people on fixed incomes, I would also consider the land-value taxation system proposed by Vern Anastasio, among others (or at least some variation of it).

3) I'm not sure that "vast" and "highly skilled" are adjectives I would apply to casino workforces. I do, however, agree that, since they appear to be here to stay, they should be made into outward looking, sidewalk interacting entertainment areas rather than windowless aluminum boxes.

Oh, I thought of a couple other things:

1) Get private contractors to take over running PGW and garbage collection. Most other city's already do this, rather than having full pentioned union workers doing it.

2) Improve the city's parks. Fairmount Park suffers from serious accessibility issues (you can't get to most places without a car and, once you're there, there's no parking). I'm opposed to building much more parking in the park, so I would propose a light rail line with gifts shops/concessions at each station. The stations should also be located within walking distance of some of the park's more prominent locations (Mann Center, Japanese Garden, etc).