Skipthegames seems to be the closest thing to BackPage.
There are a hell of a lot of listings every day, and at least 50% of the listings are actually real.
Almost all of the real listings are for girls who are charging reasonable, realistic rates - around $100/QV $150/HHR $200/HR
Yeah, about half the ads are fake, but they are easy to spot.
How? Well, where it says "LOCATION", if it says USA or INCALL or ANYWHERE or something nebulous like that then it's fake. If it says Philadelphia or Northeast or Philly/Bensalem/Cherry Hill, or anything local like that, then chances are it is a real girl working locally.
Of course, ANY girl who responds to you by asking you to go to a website for "screening" is fake and just trying to get some money for nothing.
But yeah, I've looked at all the sites, and Skipthegames seems to offer far more real girls in the greater Philly area than any other site, hands down. I mean, nothing else is even close.