Synonyms for First-rate:

adj.

excellent (adjective)
capital, blue-ribbon.
good (adjective)
exemplary, laudable, benign, fine, praiseworthy, worthwhile, commendable, pleasant, nice, favorable, beneficial, good, topnotch, admirable, five-star, splendid, excellent, worthy.
highest quality (adjective)
excellent, super, superior, superb, great, best.
superior (adjective)
capital.
tiptop (adjective)
tiptop.

adv.

all (adverb)
very well.

n.

ideal, premier, incomparable, second to none, best, very good, there is no substitute for something, choice. capital, prime, boss, dandy, swell, first class, brag, superb, quality, champion, blue-ribbon, great, top, banner, tophole, terrific, bully, topflight. first-rate (noun)
super, tiptop, superior, tops, a-one, topnotch, very well, ace.

Other synonyms:

topflight, tophole, blue-ribbon. incomparable, first class. dandy, prime, champion. great. boss, terrific, best. quality. Other relevant words:
boss, swell, dandy, quality, first class, prime, great, superior, a-one, terrific, tops, best, banner, champion, very well, capital, brag, ace, super, top, incomparable, blue-ribbon, bully, topflight, choice, tiptop, ideal, superb, tophole.