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.
shoddiest shadiest shittiest chattiest chutist
giddiest muddiest shoddiest faddiest ruddiest bawdiest shadiest haddest weediest hoodiest dowdiest neediest seediest readiest headiest baddest maddest faddist leadiest rowdiest moodiest reediest saddest oddest deediest gaudiest tidiest reddest woodiest beadiest