The Olive Tap, currently located in the Pittsburgh Public Market building, but moving shortly to a different location in the strip.
First off, the staff here is funny and informative. A very laid back and casual team who is willing to answer all your questions. Tell them what you are cooking and they will be able to recommend numerous different olive oils and vinegars for you to try.
There are dozens of olive oil and vinegars around the store, along with some other spices. You are able to sample as many oils and vinegars as you can handle. Each olive oil is available in different sized bottles for purchase. Do the prices seem expensive, certainly, but you are paying for the quality, which is extremely high. Thus the higher price works for me as you are really paying for what you get. This is not your average mass produced grocery store bought olive oil or vinegar.
If you are looking to spruce up your next salad or meal, stop in here, try the assortment of items, purchase and go to town.