For breakfast, lunch, or coffee/tea time we often go to Pure Fare on 21st Street between Sansom and Walnut. The entire place is gluten free and they have great frittatas. They also have sandwiches on gluten free bread, salads, smoothies, and some baked goods.
Choosing a dinner spot is always much more of a debacle for us. We've been to El Rey a few times though and went again this weekend. It's a pretty good Mexican restaurant with a large gluten free menu. I recommend the nachos and pitchers of margaritas. It's a fun place to go with friends but they don't take reservations so go early or plan to wait.
Anywhere else in Philly I should be trying? I have at least 2.5 more years of hanging out there.