I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
naivest nighest
livest divest naivest vest jiviest chaffiest savviest huffiest revest puffiest fiesta vesta beefiest buffiest heaviest iffiest lievest goofiest rifest leafiest suavest leaviest devest miffiest daffiest waviest reefiest chuffiest
naives knaves knives naves navies nieves niveous