most superior in quality (of a group)

most excellent

of the highest degree or quality; a form of an adjective or adverb expressing the highest degree (usually made by adding '-est' or with 'most'), such as 'happiest', 'longest', 'worst', 'most likely'

excellent, first-class

highest in rank or authority; most important; greatest

greatest, principal

(especially) nit having been defeated or surpassed

undefeated

having no equal

superlative