A clip of her singing "Let's Keep Smilin'" is the oft-repeated theme song for Orange Livebox commercials, and has millions of viewers snapping and singing along with "ho, ho, ho, ho -- HA!" Whether they want to or not.
Doris Day immortalized Paris of course, not only in the film and song versions of April in Paris, but also "I Love Paris."
Curiously, April in Paris was filmed entirely on the Warner Brother's set in beautiful downtown Burbank. And since Doris Day admits that she is afraid of flying, I wonder if she's ever been here in person at all. Oh well. We still love Paris, too. Even in February.