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.
fawniest fainest fenniest finniest funniest finest funest fancied funnest vainest viniest phoniest veiniest finessed fenced
boniest sheeniest tawniest punniest rainiest viniest looniest whinniest piniest luniest sunniest veiniest tiniest wenniest ginniest runniest bonniest zaniest fenniest fawniest waniest teeniest weeniest tinniest toniest gooniest liniest winiest shiniest downiest puniest mooniest funniest whiniest finniest phoniest canniest nest keenest renest soonest tanist sanest meanest boneset tennist honest funest leanest dunnest fainest hymnist honesty funnest pianist tannest monist hygienist cineast wannest finest vainest neist