Possibly now viewed as quite uncool:
Julie London, 'Around Midnight' album1960
Doris Day, Secret Love among many others
Lani Hall (already mentioned) Sergio Mendez &B66 'Equinox' 1967
Swingle Singers, especially with Christiane Legrand (Michel's sister), but the modern incarnations are also good and well recorded, e.g. Bach hits back
Surprised not to see Sarah Vaughn mentioned yet...