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.
essay ess easy es ease
assay essay bioassay missay say gussy hissy quassia ossa hussy mussy lyssa fussy cassia messy gassy missy assai tussah says ossia fossa cissy fossae massy bassy bossy mossy kissy naysay massa pussy lossy resay sassy sissy wussy