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.
hadst haddest headset headiest headstay hoodiest hideosity haughtiest hottest hootiest
hadst adust wadset deadest sawdust saddest retaste odist nudist modest maddest dust taste tasty toast toasty dost bedsit nudest didst dadaist sadist rudest reddest oddest midst baddest loudest lewdest headset haddest feudist faddist widest