City Blends is a local sports nutrition store that is run by a bodybuilder/science teacher named Troy. They have all the latest supplements, nutritional products and advice to go with it. You can also get a smoothie made to order. You can relax at the smoothie bar and watch sports on the big plasma TV or lounge at one of the tables in the front of the store.
They carry all the major brands and Troy will hook you up with samples of anything he's got available to try out.
Prices are reasonable, about the same as mail order by the time you include shipping but lower than a retailer like GNC.