I've seen enough 60 year-old guys with messy dark green blotches to put me off getting a tattoo. On the other hand, tattoo technology is probably much improved since said guys got their tats.
Still, if you end up not liking it or regretting at some point in the future, getting rid of it is not easy. I think there are better ways of expressing whatever it is people try to express with tattoos. And besides, it's not that original any more.
That said, very occasionally I see a pretty girl with an original, not horribly obvious and well-placed tattoo and I think "that looks sexy".