The List
There are 116 6 letter words with W as the last letter. The highest scoring is POWWOW at 17 points in Scrabble, though Words With Friends prefers JIGSAW at 20. 11 carry three or more vowels, which makes them useful for dumping a vowel-clogged rack.
ACCREWACKNEWACKNOWANYHOWBALLOWBARLOWBARROWBASHAWBEGNAWBELLOWBESNOWBESTOWBILLOWBORROWBOWSAWBOWWOWBURROWBYELAWBYRLAWCALLOWCASHAWCASHEWCURFEWCURLEWCUSHAWDECLAWDECREWERENOWESCHEWESCROWFALLOWFARROWFELLOWFOGBOWFOLLOWFORHOWFURROWGALLOWGEEGAWGEWGAWGUFFAWHALLOWHARROWHAYMOWHEEHAWHOLLOWINFLOWJIGSAWKOWTOWLEASOWMALLOWMARROWMATLOWMEADOWMELLOWMILDEWMINNOWMISSAWMORROWNARROWNEPHEWONFLOWOUTLAWOUTROWOUTSAWPADSAWPAWPAWPILLOWPITSAWPOWWAWPOWWOWPRELAWPURSEWREAVOWRECHEWREDRAWREDREWREFLEWREFLOWREGLOWREGREWREGROWREPLOWRESHOWRESKEWREVIEWRIPSAWSALLOWSEESAWSHADOWSORROWSUBDEWSUNBOWSUNDEWTALLOWTARROWTATTOWUNCLEWUNDRAWUNDREWUNSTOWUNTHAWUPBLEWUPBLOWUPDRAWUPDREWUPFLOWUPGREWUPGROWWALLOWWARSAWWILLOWWINDOWWINNOWYARROWYELLOW