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.
greasier greaser creasier grassier grazier gorsier creaser grazer crosier crazier grouser crasser cuirassier grosser caresser grocer curser crosser crozier cruiser coarser grocery courser corsair kreuzer carouser cruzeiro crosshair curiouser crozer cursor
brasier creasier greasier tarsier drossier raiser pursier raser prissier rosier parser gorsier brassier greaser grassier cuirassier racier creaser brassiere crosier frowsier drowsier dressier prosier praiser brazier crasser crazier horsier hoarser harasser eraser grazier coarser tressier
grease greasy crease creasy gores grass grassy grays grees greys grues egress ogres ogress