As it would take an age to go through what everyone else has written to check if this has already been posted.

Rolling in the Dew
Colcannon
SUMMER WINE
LUKEY'S BOAT
I'LL TELL MY MA
Seven Days are in the week [ ALMOST EVERY CIRCUMSTANCE]
DASHING AWAY WITH THE SMOOTHING IRON
(a Xmas one) - HOLLY BEARS A BERRY


(with a few of these you kind of have to be prepared to sing the boys part, but they all sound nice with female vocals)