I don't ascribe respect to someone simply because they have a tattoo or not. I have objections to certain offensive tattoos. But I see that as a base reason for not respecting another human being.
Personally, i'm pretty neutral about tattoos. It doesn't impress me that people try to make themselves stand out by inserting poisonous ink into their bodies in order to make some political or artistic statement. But, at the end of the day it honestly doesn't bother me that people do it.
I used to consider tattoos more of a bad, "deviant" thing, but I've come to accept them much more now. It is a personal choice to have them, and as long they're not obscene, racist, or some such, I don't have a big problem with them. The only thing I wonder about is how much people will like their tattoos when they get much older and their skin gets thin and saggy...
Anyone with a tacky tattoo doesn't deserve respect. You let someone mark your body permanently with ink? Instantly undeserving of my respect. I don't even care if they're a nice person, if they have a tacky tattoo, they're automatically jerks.