Prettiest rhymes with:
dirtiest, flightiest, heartiest, heftiest, mightiest, nastiest, rustiest, angriest, atheist, bloodiest, blotchiest, blowiest, busiest, cheeriest, chilliest, craziest, deadliest, dirtiest, earliest, easiest, fanciest, flashiest, flightiest, flimsiest, fluffiest, foggiest, friendliest, funniest, grooviest, handiest, happiest, hardiest, heartiest, heaviest, heftiest, jolliest, juiciest, junkiest, laziest, likeliest, lobbyist, luckiest, mightiest, nastiest, noisiest, raciest, rainiest, riskiest, ritziest, rustiest, scariest, sexiest, showiest, silliest, skimpiest, skinniest, sloppiest, smoggiest, sniffiest, stealthiest, steamiest, stickiest, thorniest, tiniest, trickiest, ugliest, wealthiest, worthiest, zaniest
Prettiest sounds like:
parodist, predicate, predicated, predict, predicted, pretext, prioritized, pritchett, produced, product, protect, protected, protectee, protest, protested, proudest