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.
soonest sanest sunniest sunset cineast snoozed sunsuit zaniest cineaste snowsuit sinuosity sensed synced sensate sneezed
honest soonest nest mooniest looniest gooniest meanest funnest funniest phoniest vainest veiniest finest honesty leanest punniest renest piniest cineast canniest finniest zaniest dunnest tawniest tiniest toniest wannest wenniest whinniest sheeniest oncet fenniest canoeist boneset whiniest tinniest waniest tannest teeniest sunniest downiest liniest fainest keenest bonniest boniest weeniest viniest winiest neist fawniest ginniest luniest funest monist moonset onset puniest rainiest runniest sanest shiniest