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.
renown reunion renin rennin ronion
known renown gnawn anion noun noon none nona neon onion gonion quinone munnion annona ronion tenon wanion cannon fanion anon pennon phonon inion ionone canon guenon minion ninon fanon pinon bunion pinion reunion xenon union chinone
rein renew wren arena arene bren erenow frena