A good quality lean ground beef is best in this recipe. Since you'll be adding fat with the cheese and sour cream, any extra fat will pool at the top and not be appetizing. For this reason, I suggest using lean ground beef AND draining the excess fat. If you opt for a higher content of fat, ensure to drain your beef very well. You may also need to buy a larger quantity of beef in order to have the same yield. Higher fat content beefs tend to cook down more and result in less overall browned beef.