I'm an inveterate diner fan, and Philadelphia is blessed with many. The Midtown II is a short walk from my home, and I've been there at least 200 times over the past 20 years. Particular aspects of this place that visitors will appreciate:
-a huge, 7-page menu that spans all three daily meals and includes everything you'd imagine would be available at a diner. While they specialize in typical diner fare (the breakfasts are unbeatable), they also do quite well with larger, more complicated meals. It's Greek-owned (as are many Philadelphia diners), and feature many Mediterranean specialties
-daily lunch and dinner specials that will satisfy the heartiest appetite (the dinner specials come with soup or salad, homemade bread, two vegetables and a dessert)
-very reasonable prices, whatever the order
-delivery to the local area (~10 blocks in any direction)
-open 24 hours/365 days a year!
-an adjacent bakery that not only creates some of the best desserts in the city, but also makes holiday-style cookies all year long
If there are any downsides, they're very minor (crowded for weekend breakfasts; occasionally inconsistent service). But trust a native: if diners are your thing, you could hardly do better in Philadelphia.
If you own or manage Midtown II Restaurant, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.