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.
wisha wish whish wash wich washy which witch woosh wushu whoosh witchy
geisha poisha wisha sha whish pish wish kasha dishy cushaw sashay cuish pshaw pasha cashaw knish dish heishi shah beauish bashaw shea shay shaw fishy rishi fish