I have 5 kids and 5 tattoos and I would say hands down labour is by far the worst pain.
The tattoo pain stops once they take the needle off and is very dependent on where you are having it.
Top of foot, back of neck didnt hurt at all. Side of foot was a bit ouchy, my tramp stamp was more painful in some bits than others but it is the biggest. My inside wrist was the worst of the lot. Very sensitive area.
No where near as sensitive as my Kooka though!!! Everyone of my labours hurt like hell and although some more than others give me a tattoo anyday