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.
goon goony gooney goonie gown coon gone gonia goanna gun gan con kaon gaun gane cone cony coin gaen coni conn guan gain koan coign coney guano gunny koine quoin
boon coon goon loon moon noon poon soon zoon toon shoon on