They are not the best sandwich cookie, but they are the 'default.' They're also 113 years old this year.
The original variant was the 'Double Stuf' (heh), with additional filling (heh heh).
Since 2004, there have been a number of other variants with different flavors of wafers and/or filling. (These are not true Oreos.)
Contrary to
popular belief common sense, one serving of Oreos is a single row from a package. Hence, a 'family size' package is three servings.