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.
coassist casuist cosiest gassiest coziest goosiest queasiest gauziest queaziest
assist coassist bassist mossiest fascist easiest busiest bossiest massiest newsiest mussiest nosiest resist sassiest desist cheesiest fussiest hissiest housesit lousiest mousiest gassiest necessity goosiest noisiest queasiest pussiest cosiest rosiest casuist sissiest messiest wussiest choosiest
casas cases cassias cassis casus coses