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.
tautest tattiest dottiest tattooist detest deadest dotiest tidiest duettist doughtiest dadaist
mutest cutest tautest test jettiest loudest testy goutiest matiest nattiest gnattiest meatiest autist mitiest quietest dotiest nettiest nudest bittiest cattiest outsit pettiest poutiest retest rudest sootiest detest dottiest tattiest wattest whitest wittiest chutist battiest outsat coattest doughtiest ruttiest pottiest rattiest outset peatiest nittiest nuttiest testa hootiest neatest zootiest rootiest latest lutist guttiest hottest haughtiest fattest phattest footiest fittest featest fattiest knottiest attest wettest whitiest chattiest shittiest