Here's my take on the options available in Center City:
* Capogiro: definitely the best in terms of interesting and innovative flavors (love the dark chocolate and the hazelnut baccio) , and the texture is creamy without being overwhelming (probably because it's gelato instead of ice cream). My favorite!
* Franklin Fountain: more "traditional" than capogiro in terms of flavors but the ice cream sundaes and the floats can't be beat!
* Scoop DeVille: really yummy mix-in combos are the highlight of this place. The flavors and toppings alone aren't that special, but mixed all together they are amazing!
* Sweet Endings: fro-yo with do-your-own toppings. The toppings are mostly fruit, so it's a healthy option, but the flavors of the fro-yo itself aren't anything to write home about
* Yogorino: more European-style, the fro-yo truly tastes like frozen yogurt (i.e. the tangy, not super sweet flavor of yogurt) instead of ice cream. The toppings are good, and it's not as heavy as other do-your-own topping places.
* Sprinkles: this might be kind of far because it's in University City, but I LOVE this place! Mix-and-match flavors of non-fat (but still tasty) fro-yo, and tons of toppings to choose from. Definitely better than Sweet Endings.