Denotive:
di·va
Pronunciation: 'dE-v&
Function: noun
Inflected Form(s): plural divas or di·ve /-(")vA/
Etymology: Italian, literally, goddess, from Latin, feminine of divus divine, god -- more at DEITY
Connotative:
Larger than life, affected stardom, perpetual notoriety, full of oneself
Several on the poll fit these descriptions, some do not.
As for voices, my choices would have to be Ella, Whitney and Barbara. Flawless.