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.
suddenness soddenness suddens saddens soddens sadness seediness soudans soutanes stuns sootiness setons sedans stanes steins stenos stones cetanes sateens seitans stannous
hiddenness soddenness rottenness woodenness suddenness leadenness nudeness wideness mateyness wetness dueness dunness tennies meetness quietness cuteness rudeness lateness liteness muteness whiteness redness