We like Optimum Nutrition. The Natural vanilla tastes a bit like paper though. The Gold standard cookies and cream is pretty good. My husband uses the pro complex vanilla flavor, too many calories for me! Also, if you can find it, Scitec Nutrition has some yummy flavors. My fave is the chocolate coconut (www.scitec.com)
You can get just about any brand or flavor of protien powder (its alot cheaper than GNC) here : www.advantagesupplements.com