Here are several numbers by the legendary Bing Crosby, who sold more than one billion records, being the absolute record holder in this category! But he was most of all a great singer, a crooner and also a distinguished actor.
That's jazz (with Louis Armstrong, from the movie High Society, 1956)
Duets and medleys
with Andy Williams
with Dean Martin
with Dean Martin and Lena Horne
with Pearl Bailey