Te best cookbook is...the one that fits your cooking and eating style,
i.e. one that you will use and refer to often.

Mine used to be Fanny Farmer ca 1965 ed. and the old Joy of Cooking.
More recently I rarely use a cookbook, but when I do, it's often one of
the first two in the Colorado Jr. Women's League series: Colorado Cache
and Taste of Colorado. Both have some terrific recipes for entertaining.

I also often refer to rfc archives via Google, and the rfc cookbook.

I agree with (was it Christine?) who said she reads her cookbooks for
entertainment like novels.

gloria p