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.
baffy baff biffy buffy biff boff buff beefy boffo buffi buffo bouffe beef bevy
baffy daffy taffy chaffy aff pouffy chuffy buffy chaff gaffe toffy raff jiffy caff baff miffy iffy biffy naff piaffe puffy daff gaff quaff waff huffy leafy yaff