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.
union
bunion wanion fanion inion pinion minion reunion munnion union onion ronion anion gonion pinon banian quinone guanin known conine nona venin panino panini rennin none annona neon quinine venine canon pennine tannin xenon aeonian chinone conin dynein guanine renin pennon ninon benign quinina kinin eonian guenon quinin nine noon canine leonine cannon ionone fanon linin noun anon tenon renown oniony hyenine