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.
rudder ruddier ruder rudery redder ridder rider reader raider router redear reedier ruttier readier reutter rowdier retry redry rater retro radar rotter rooter ritter retore redraw retear rioter retire redrew ratter writer rattier retiree rootier
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
rudd ruddy redd rude rued crud cruddy crude prude