The front of the card is excellent (Guy Kawasaki), but I hate the back. In my mind, the most important part, after the name, is how to actually contact you. On Guy's card, that info just blends in with his three websites (seriously, he needs to put all three?). I like the simplicity, but my experience with all black business cards has been that it really sucks you can't write on them.
I'm such a whore for black business cards. My personal business/freelance business card is black but it's also matte (http://www.flickr.com/photos/chix0r/1409350187/), and half of one side is not black. It's entirely possible to write on it..I haven't had many problems with that, and even if you write on the black part, you can usually read most pen/pencil marks on it. In the event you can't read it straight on, tilting at an angle usually does the trick.
Some of mine are braille embossed though, but the people I give those to usually don't need to write anything on it.
It's the glossy black ones that are more annoying to me.
