Are you looking for fresh herbs or dried? If you are looking for fresh, check out your local farmer's market or call around and see where restaurants are getting their stuff, if locally. As far as dried herbs and spices go, I am a big Penzey's fan. They are a spice store with a number of outlets across the country and a great online store. The spices are great, but you will pay a premium price for them. Well, worth the extra money as far as I am concerned. Check out their website at:
http://www.penzeys.com/cgi-bin/penzeys/shophome.html