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.
keenest canniest gooniest canst queenside gainst canasta
renest keenest nest hygienist fawniest leanest boniest gooniest canniest fainest punniest piniest meanest looniest boneset ginniest viniest cineast soonest zaniest dunnest tawniest tiniest toniest wannest wenniest whinniest sheeniest honesty neist finest bonniest whiniest tinniest waniest tannest teeniest sunniest downiest runniest sanest funest fenniest weeniest finniest winiest rainiest puniest mooniest luniest honest liniest veiniest vainest phoniest funniest funnest shiniest
keenness keens akenes skeens skenes