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.
retains reattains retines retinas retinues rutins ratans redans readiness retenes rattans radians ratines retunes routines ratanies ruttiness rootiness reediness radons redons rattens rhytons rattons ratoons reddens redness ratteens rattoons redenies rudeness radiancy routinize rowdiness ruddiness rottenness
tains attains detains stains reattains retains tins tans tines rutins latinas ratans luteins retinas seitans cutins latinos mattins routines cetanes gitanos rattans patins zeatins stanes shaitans soutanes tansy patinas biotins tetanus betaines mutines retines patines phytins satins butanes matins witans phytanes poutines lattins ratines steins titans chitins cotans sheitans
retain retina retinae retine retinue cretin