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.
rowdiest readiest reediest rootiest ruddiest rudest reddest rattiest roadside ruttiest retest retaste redecide
beadiest tidiest readiest reediest neediest ruddiest woodiest weediest faddiest gaudiest moodiest shoddiest shadiest dowdiest rowdiest headiest giddiest seediest deediest muddiest hoodiest leadiest bawdiest footiest nudist sootiest doughiest oddest gnattiest maddest battiest bittiest ruttiest jettiest feudist pettiest nittiest cattiest rattiest shittiest lewdest loudest fideist odist dotiest modesty chattiest deist rootiest whitiest dottiest wittiest pottiest poutiest mitiest nattiest widest peatiest deadest tattiest sadist doest nettiest judoist hootiest matiest guttiest nuttiest fattiest doughtiest meatiest podesta faddist modiste rudest goutiest zootiest didst reddest modest whitest saddest baddest nudest dadaist knottiest haddest haughtiest
rowdies roadies crowdies crowds