We handle many certified coins.  The top certified grading companies on the market today are: 

NGC (Numismatic Guaranty Corporation)

PCGS (Professional Coin Grading Service)  

Nunemaker's Coin Shop buys, sells, and trades in NGC and PCGS certified coins.  We are an authorized dealer for NGC.  Certified coins are also referred to as "Slabs" in the coin industry.