I think they are wonderful. I only have one, and for the time being it's enough for me but there is really that part of my soul that could get decked out (tastefully) from head to toe in images & words that have deep meanings to me. As a woman I find the majority of tattoos on men ravishingly attractive, and those on other women very beautiful.
I tend to think that if the tattoo was entered into with the right frame of mind (lol, as oppressed to 12 beers making the judgment calls for you) and after a bit of consideration, the wearer will usually display it (or them) in a way that conveys that he or she is happy with their tattoo art. And that sense of happiness with their tat(s) makes the particular design look good on that person. What works on one person doesn't always look as good (or “fitting”) on another.
I love the sense of permanence that a tattoo implies (I know that they can now be “removed”, but for most people our skin art is a lifelong companion). Something about the choice to commit yourself to modifying your body for the rest of your days is very appealing to me.