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