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.
gosh cosh gash gush gushy gotcha gouache cash coach cooch couch cuish cushy kasha quash
bosh josh cosh gosh mosh nosh posh tosh whoosh woosh sh