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.
gassy gawsy gauss gussy gas gaes gays goas goosy gauzy quass guess kissy causey goosey queasy gussie gawsie cassia kas quassia gos cosy gaze koss cuss keas kaas caws cays goys goos case goes coss guys kaes kays kiss koas casa
gassy massy sassy bassy ass sass wrasse passe mussy missy easy assay queasy messy fussy bioassay lasso lass quass gussy sissy tass wussy gawsy missay masse essay bassi hissy lassi hussy lossy gauss bossy bass massa mass mossy pass pussy cissy kissy basso daisy tasse chasse