Lewis, the more formal and phonetic spelling of the French Louis has been in the Top 3 in Scotland since 2000, and is one that parents in the U.S. are just beginning to rethink.
Lewis was a Top 100 name in this country from 1880 to 1930, reaching Number 30 in 1880. One of its most famous namesakes is Lewis Carroll--born Charles; a current bearer is comedian Lewis Black. Lewis is also a very common surname, as in Lewis & Clark, Jerry Lewis, Jerry Lee Lewis, Daniel Day Lewis, Sinclair Lewis, Leona Lewis, and many other notables. Louis Armstrong pronounced his first name as Lewis.
Lewis is currently Number 202 on Nameberry, while Louis, the choice of Sandra Bullock for her son, is 134.
Nickname/middle name Lou is making a comeback for girls (as in Keri Russell's Willa Lou), so why not Lew for boys?