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.
quietist quietest gaudiest goutiest guttiest cutest cattiest
quietist pietist deist fideist fattiest bittiest battiest batiste nittiest autist lutist gnattiest meatiest footiest poutiest retest ruttiest zootiest dotiest doughtiest tattiest wittiest chutist nattiest jettiest haughtiest peatiest goutiest guttiest quietest matiest mitiest knottiest cattiest nettiest nuttiest hootiest pettiest pottiest rattiest rootiest sootiest detest dottiest duettist whitiest chattiest shittiest
quiets quietus quits quoits equites equities