Great atmosphere, drinks and staff make this watering hole set up by refugees from New York one of the best bars in Pittsburgh. The downstairs is the main bar area. It's a nice layout that get redecorated fairly regularly. Only drawback is that it can get really crowded on Pub night (Wednesdays) and weekends. On weeknights, you can usually get a seat at the bar or in a booth. Even when it's busy, though, the bar staff is quick with your order. Brian is an amazing bar tender. Maybe second only to Tim over at Gooski's. They also have a good brunch on Sundays that is open 12pm until late into the afternoon.
Upstairs is basically a variety hour. You can stumble upon almost any kind of music there. A week after seeing the Cults play a 4,000 person venue in Amsterdam from a balcony, I saw them on Wednesday one person back in the upstairs in Brillo ($8!). Amazing.