Tonic makes arguably the best mixed drinks in Pittsburgh that I've had to date. They make the best vodka tonic I've had in town, and the most respectable mojito I've had yet in Pittsburgh. My wife loves the martini menu, especially the lemon drops. There's also a drink called the "Buzz Lightyear":
buzz lightyear
stoli strawberry, triple sec & tang
Gotta respect any bar that uses tang. Check out this drink menu:
http://www.tonicpittsburgh.com/drinks.html
The service is OK depending on how busy it is, but service at the bar is typically very good. The food isn't bad, just not the primary reason why I go there. They have most of the standard fare - wraps and sandwiches.
This is a great happy hour place.