Depends on a lot of things - how much you value conditioning, how far from the Burgh you're willing to travel, how much you're willing to pay, etc.
On the $$$ end, there's basically Mystic Rock and Olde Stonewall. Neither wow me personally and neither is remotely worth the $$$ - but they are good solid golf courses. Many other people - maybe most other people, actually - have much higher opinions of both than yours truly.
My own personal favorite public course (aside from my beat up home muni, which will always be special for personal reasons) is Quicksilver. They used to host a Senior Tour event there and now they host a Hooters Tour event. It's very reasonably priced - $55 last I checked - but I haven't been there this year so I have no idea what kind of shape it's in. It's been a relatively rain free summer (especially for the Burgh, JohnV wouldn't believe it if he had stuck around
), so the budget courses are likely in rougher shape than the courses with $$ (especially the many wonderful old private courses we have here - wish I could help you out there, but I'm a public golfer myself).
Birdsfoot is thought highly of by some, but it suffers from many of the same problems that most Burgh public courses do - very difficult terrain, which causes the occasional awkward hole. It's no surprise that the older courses are more highly regarded, as they have the choice land.
Let me know if you feel like grabbing a beer, or need help with directions. Pittsburgh is second only to Boston among the many places I've been to in terms of finding your way around - hope you either have a damn good map or GPS.