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.
faddist faddiest feudist fideist fattiest fattest featest fittest footiest voodooist
faddist deist rowdiest reddest odist muddiest nudist baddest bawdiest beadiest modiste faddiest feudist dowdiest deediest weediest seediest shadiest saddest fideist haddest judoist reediest readiest oddest moodiest neediest leadiest gaudiest maddest headiest giddiest hoodiest didst dadaist tidiest sadist woodiest ruddiest shoddiest