If you're looking for diner food in an especially colloquial way, look no further than Nancy's Restaurant. The sign out front says "Nancy's" and the eponymous title is flanked by breakfast in front of clouds, like breakfast in the upper atmospheric climbs. I dare say this restaurant leans towards "Diner"; it has the feel that your day could start here.
On Saturdays they serve breakfast ALL DAY. The rest of the week b-fast stays in the AM and club sandwiches and something called "Steak-um" gets served...
Though the food did not wow me, the comfort of interaction with our waitress and other diners did. Nancy's has a sense of community and as a stroll around Wilkinsburg offered further, there are few places in Wilkinsburg that seem to be so bustling.
For an extra treat stop in to the pawn shop next door- run by nice guys who just might cut you a post-breakfast deal.