unexcelled
adjective
un·ex·celled ˌən-ik-ˈseld 
: incapable of being bettered or improved upon : unsurpassed, superb
unexcelled craftsmanship
an unexcelled performance
a landscape unexcelled in its beauty
The mess of brains given me by the Great Wizard is considered by my friends to be unexcelled.
L. Frank Baum
L. Frank Baum
Word History
First Known Use
circa 1800, in the meaning defined above