For me the song that most brings to mind Andy Williams is not "Moon River," perhaps his most famous work, but instead his 1967 hit "Music to Watch Girls By." Here I must point out that Mr. Williams' cover of the song was not the original. In fact, it had its origins as an instrumental written for a Diet Pepsi commercial in 1967. The Bob Crewe Generation did their own version of this Pepsi instrumental, going all the way to #15 on the Billboard chart with it. Later that year Andy Williams did his own version of the song, with one major difference. Being a singer, Andy Williams' version had lyrics.
Here is a mash up someone did a while back of Andy Williams' version of "Music to Watch Girls By" and clips from one of my favourite TV shows, The Man From U.N.C.L.E.