Someone has already mentioned Mary as a name that has died out for girls. When I was at school Mary & Ann(e) were the most common middle names for girls - Ann also seems to have disappeared for both middle & first names now.
Some of the older names in my tree now rarely seen -
Elsie, Lilian, Fanny, Ethel, Doris, Joan, Jean, Doris, Dorothy, Hilda, Phyllis, Minnie
Frank, Albert, Ernest, Robert, John, Leonard, Percy