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.
madder mudder muddier madeira madre mater maduro matier matter moodier mattery meatier metro muter miter meter metre mature meeter meteor metier midair mitier mooter mutter moidore
badder dodder nodder codder budder bedder judder madder sadder kidder chudder redder adder mudder wadder shedder ridder udder shudder tedder wedder bidder odder widder ladder fodder rudder padder gadder rowdier seder deer kneader rider lauder heder needier tidier guider lewder weedier rudery bawdier gaudier seeder wider chider leadier dowdier deedier chuddar reedier shader nuder cheddar raider ceder powdery giddier moodier lader ruddier hider leader feeder needer woodier doer weeder reader powder bider dere dear headier loader louder hoodier lieder fader cider deader cyder gaudery voider faddier header ruder eider muddier doddery seedier siddur redear heeder beadier readier shoddier aider wader coder cheder chowder beader shadier shuddery
mad made maid maud mayday mead meadow meadowy midday middy muddy amadou