Sichuan Gourmet further up the road was my first introduction to legitimate Sichuan Chinese cuisine here in Pittsburgh. While I still love SG, Chengdu takes top prize based on my first two times here. Probably best for take out more often than not, unless you're after one of their flaming pan dishes, which are great.
I've had their pork dumplings in spicy red chili sauce, quonqing (crispy) chicken, and three cup chicken. Both are perfect dishes.
They have plenty of unique offerings like rabbit, frog.