Here's a selection I have mostly from WW1. I'm sure there are others around and probably some better examples than I have.

From the top left
Centrecast throwing practice found buried near Ypres - unusual early type - well used and battered.
Standard Mills No5 undrilled for filler or striker ( found at the side of a canal in Lancashire!) Again well used.
Townsend style grenade
Possible WW2 Home Guard type but may be earlier
Unusual No 5 type with wings.
White No 5 with moulded in lever
No 36 Dated 1917 in aluminium or similar - probably to be filled with clay or cement.
Please add your own variants.
John

From the top left
Centrecast throwing practice found buried near Ypres - unusual early type - well used and battered.
Standard Mills No5 undrilled for filler or striker ( found at the side of a canal in Lancashire!) Again well used.
Townsend style grenade
Possible WW2 Home Guard type but may be earlier
Unusual No 5 type with wings.
White No 5 with moulded in lever
No 36 Dated 1917 in aluminium or similar - probably to be filled with clay or cement.
Please add your own variants.
John