In Pittsburgh I would recommend:
Saks Fifth Avenue - downtown (carries the usual Saks stock)
Larrimors - downtown (AdP, SMN, Truefitt)
Toadflax - Walnut St. Shadyside(wide niche selection)
Schillers Drugs - Walnut St. Shadyside (wide niche selection).
Sephora - Walnut St. Shadyside
As you are looking specifically for Creed, you can find them at Saks and at Schillers. My recommendation is to visit the Shadyside area (near Pitt and CMU) as it is a pretty cool area.
Send me a message if you need help.