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.
knottiest nattiest nettiest nittiest nuttiest gnattiest neatest noticed neediest nudest nudist
battiest nettiest nuttiest dottiest wittiest cattiest rattiest fattiest knottiest nittiest shittiest bittiest pottiest pettiest nattiest guttiest jettiest gnattiest tattiest chattiest ruttiest coattest poutiest dotiest goutiest haughtiest duettist wattest fattest zootiest rootiest meatiest phattest attest whitiest hootiest sootiest footiest doughtiest fittest peatiest hottest wettest mitiest matiest test