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.
mopey mope mopy mop map
ropey dopey mopey ope mope mopy nope hoopoe roupy soppy loupe dope lope dopy coupe topee whoopee choppy hoppy loppy goopy pope rope copy poppy ropy cope soapy copay loopy soupy tope hope typey whoopie shoppe