This is the one that popped into my mind immediately: http://www.juliancoin.com/ The dealer is well know and respected in the numismatic community.
Golden Eagle Coin in Laurel Maryland is very good. However they tend to get a bit swamped with Bullion buyers and sellers. It's kind of a funny place with an antique/junk shop in the front of the store ... and coins out the wazoo in the back http://www.goldeneaglecoin.com
