Rey Azteca has easily the best Mexican food in the Pittsburgh area. It is my favorite restaurant and is at an amazing price. I have eaten at expensive prestigious eateries, but Rey Azteca beats them all!
For lunch, I always get combo 12-the flautas are to die for! And dinner I usually get combo 17-beef burrito and a chicken enchilada. The quesadillas are so delicately crunchy and salsa is so fresh and smooth...certainly a must try if you're in the area!
The only thing one could possibly dislike is the decor is rather lacking and the walls are a ghastly green and purple. But wouldn't care if I had to eat in the basement, the food is so amazing!
TL;DR
So all in all, Rey Azteca is a fantastic restaurant for the best Mexican food in the Pittsburgh area. Not exactly aesthetically on point, but it has delicious food at a great price.