A-one

adj. A 1, excellent, outstanding; of first quality, first rate, of the highest quality, quality "A"; first class; first rate

Adjective
1. of the highest quality; "an ace reporter"; "a crack shot"; "a first-rate golfer"; "a super party"; "played top-notch tennis"; "an athlete in tiptop condition"; "she is absolutely tops"
(synonym) ace, crack, first-rate, super, tiptop, topnotch, tops(p)
(similar) superior
(classification) colloquialism