Neither. 1 or 2 ear piercings are the only ones that I think look good (in the ear lobe, not helix style), and tattoos are nasty as well. The natural look is the way to go, if you ruin all of your natural beauty with these fancy tattoos and piercings then that makes me less attracted. And let me put it this way:
If you have these things I highly doubt it will make a guy want to date you. I have never heard a guy say "I am going to date that girl because she has tattoos and a helix piercing" it just doesn't happen, but you might turn off certain guys by having these things because, lets face it, some guys just think they look bad like myself. So if you want my opinion, I say dont get them because they won't do you any good.
Personally, I'm not into a load of piercings. I'm cool with regular ear piercings and helix piercings, and if you have a couple more, but I definitely am not a fan of people who are covered in holes plugged with metal.
I think it's all about expression and style: I personally like piercings and tattoos (within reason) yet I have none, simply because it doesn't reflect my style. I'm not closed-minded enough to think poorly of somebody based solely on tattoos or piercings.