Here's my top ten representative English folksongs (not necessarily my favourites but ones that encapsulate the English tradition)

Banks of Sweet Primroses
Buttercup Joe
The Outlandish Knight
Barley Mow
All Jolly Fellows that follow the plough
Green Bushes
Nutting Girl
The Blacksmith
A Sailor coming home one night (Died for Love)
Seeds of Love

Gwilym