insufficient, meager (or meagre), mean, miserly, poor, scanty, shabby, short, skimpy, spare, stingy

insufferable, intolerable, unbearable, unendurable

atrocious, execrable, miserable, vile, wretched

exceptional, exquisite, extreme, fancy, first-class, high-grade, matchless, maximized, maximum, optimal, optimum, peerless, preeminent, premium, special, supreme, unmatched, unparalleled

A1, bang-up, banner, boss [slang], capital, classic, crackerjack, dandy, divine, fabulous, first-rate, grand, great, groovy, heavenly, jim-dandy, keen, marvelous (or marvellous), neat, nifty, noble, par excellence, prime, sensational, splendid, stellar, sterling, superb, superior, superlative, supernal, swell, terrific, tip-top, top, top-notch, unsurpassed, wonderful