Alma de Cuba (16th and Walnut): At Stephen Starr and Douglas Rodrigues's Nuevo Latino restaurante, people come for the mojitos, but stay for the bold flavors. With the restaurant week options of starters at $12.50, main meals at $26.5+, and dessert at $9, Alma de Cuba gives back pretty generously for your $35. Their Ceviche dishes were only mentioned in 135 reviews on Yelp; Alma de Cuba may be worth checking out for that alone.
Buddakan (4th and Chestnut): Buddakan is yet another Stephen Starr restaurant, but that doesn't mean it's any less sexy and swanky. Still going strong after 15 years, this Asian fusion restaurant in Old City is beautiful inside and out. With the starters normally priced at $12.5–14, and main dishes ranging from $24–34, the $35 payment seems rather minimal. Stick around for Dip Sum Donuts because they are as delicious as they are witty: five spice sugar doughnuts that come with blackberry jam, chocolate sauce, and gingered cream cheese. Who would have thought? Stephen Starr did.
Tinto (20th and Chestnut): Despite the small portions, Iron Chef Jose Garces' Spanish tapas restaurant will win you over with huge flavors (especially their duck confit montaditos). If you are into variety, this is the place for you. The comprehensive restaurant week menu is almost identical to the regular a la carte menu, giving you options on options on options. Both the first and the second course allow you to choose two dishes, usually ranging from $7-14. On average, you would have spent $40, and if you did it the right way, you would have spent $56. So, go crazy with the appetizers, your taste buds will be satisfied without having to worry about the calories. Bottom line: do the math; go to Tinto.
Check out the full restaurant week list right here.