For me personally i just wanted to try one and see if it really hurt as much as some people say, i heard stories about people fainting whilst getting a tattoo, i would never have had a Tattoo years ago when they all seemed to be coloured, they look really bad on people after a few years when they faded and there was never any decent designs etc, now there are some fantastic Tattoo designs out there, i think it is in our Genes/History etc whatever you want to call it, most ancient tribes in whichever country usually sported Tattoos of some sort, probably thought it made them look more fierce.
http://www.tattoosymbol.com/celtic/ancient_celtic.html
http://www.wearetheenglish.com/tattoo.html
http://www.vanishingtattoo.com/ancient_tattoos_1.htm