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.
mootness moodiness meetness matiness muteness mateyness meatiness mutines moutons madness matinees mutinies muddiness matins mutons mattins mittens muttons madonnas
fatness witness patness tautness meetness fitness whatness hotness mootness neatness quietness wetness matiness nuttiness beadiness phytanes hiddenness madness jettiness mateyness jitneys headiness meatiness ruddiness haughtiness tunes lateness muteness rootiness battiness ruttiness atones giddiness gaudiness muddiness stones butanes shadiness chutnees woodiness wittiness butenes soutanes whiteness mutines titaness doughtiness goutiness duotones knottiness deadness loudness sadness soddenness ketones bittiness cattiness lewdness pettiness retunes oddness tynes tidiness nudeness rowdiness voidness tones patines retines moodiness liteness goodness routines pottiness weediness nattiness ketenes leadenness rudeness attunes tattiness poutines retenes tines cetanes dueness sootiness badness bawdiness cuteness redness neediness fattiness reediness wideness dunness readiness stanes seediness suddenness dottiness rottenness dowdiness ratines witneys woodenness chattiness chutneys shoddiness