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.
gaffes gaffs cafes caffs guffs quaffs coiffes guffaws coffees kafs coffs cuffs goofs kaifs caves coiffeuse cavies guavas quiffs
bouffes coiffes piaffes gaffes ruffes pouffes fes effs toffs teffs diffs quiffs guffs fees toffees daffs biffies miffs waffies duffs ruffs whiffs fess fifes huffs chuffs chafes feoffs feoffees jiffies fehs feus cafes baffies foes buffs muffs coffees boffs deifies knifes biffs tiffs puffs doffs tuffs wifes buffos safes coffs cuffs gaffs quaffs dieoffs taffies toffies baffs waffs luffas naffs roofies defies raffs reifies pouffs offs riffs jiffs howffs boffos jefes caffs luffs wifeys chaffs yaffs