They are a bunch a good ice cream places in Philly. But there are only a few that are top notch, at least on my list.
Philly Flavors on Fairmount Avenue is awesome. There are tons of flavors and even have sugar free for those who are diabetics, which makes them great.
Scoop DeVille on 13th and Walnut Street is another awesome ice cream shop. The staff is wonderful and they have so many options of flavors, it can be a bit overwhelming. Unless you like staring at a menu for several minutes.
The Franklin Fountain on Market Street in Old City is most people's favorite. The place has an old time feel with some really original flavors to pick from.
Custards and Cakes Creamery is another good one in my opinion. Parking can be a bit trivial, but once you figure your way around it's on to the good stuff. Their sundae are second to none and the staff is really friendly.
Lastly, Capogiro in Rittenhouse Square is a treat, literally. Aside from the normal ice cream, they are king of the sorbet and gelato. Take your pick, all their choices are to die for.