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.
whitest whitiest wittiest widest wattest wettest weediest woodiest whatsit wetsuit
whitest test hoodiest rattiest pottiest peatiest fattest neediest coattest bawdiest nattiest attest hottest beadiest gaudiest mitiest zootiest reediest jettiest latest matiest guttiest wettest shittiest rootiest chattiest wittiest ruddiest whitiest seediest wattest detest dottiest haughtiest dowdiest battiest testa tautest testy gnattiest muddiest doughiest featest footiest poutiest nuttiest pettiest headiest ruttiest deediest knottiest neatest readiest cutest quietest goutiest bittiest weediest meatiest giddiest cattiest faddiest sootiest moodiest dotiest leadiest mutest nettiest hootiest fittest tidiest fattiest doughtiest phattest retest nittiest widest tattiest woodiest shadiest rowdiest shoddiest
whites whiteys whities whits wites