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.
shatter chatter shutter chattier shittier chattery shader sheeter shadier shouter chitter shooter cheater shedder shudder shoddier shuddery shoetree chadar chider chadri chador cheder cheddar chowder chuddar chudder
fatter latter batter hatter ratter phatter watter yatter tatter natter chatter shatter patter matter guttery potter otter litter nattier puttier tater jittery knitter jotter cottier bitter pottier heater pottery seater butter mutter nuttier matier nittier baiter rotter letter petter gater jitter tetter shutter knottier sitter cheater chattery whetter wetter waiter tuatera totter titter tattier oater nettier attar watery wittier fitter reutter better feater netter meatier dotter nutter coater rater guttier mater ritter putter knotter boater cutter titer cotter hitter cattery buttery lottery eatery bittier quitter eater lotter fetter getter gnattier gaiter cater gutter beater battery pettier vetter battier tauter hater jettier pater littery fattier ruttier mattery dater setter peatier rattier chitter neater toter tottery utter water later wheatear whitter dottier cattier chattier shittier hotter
shat chatty shittah shitty shoat shott