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.
deafest deffest daffiest devest divest defaced deficit defused defuzed devised
deafest safest fest chuffest chaffiest goofiest feist beefiest buffest buffiest huffiest feast iffiest leafiest reefiest rifest daffiest liefest suavest deffest miffiest chiefest puffiest chuffiest