Cling-mounted rubber is my first choice, then wood-mounted rubber. I have to reeeeeeeally love the image to buy a clear stamp. They're softer and I'm prone to pressing too hard and getting a blurred image. And to give myself some slack, I know that sometimes it's truly not my fault the image isn't crisp. I think rubber just gives a crisper image than clear.
You had me at, "We shouldn't be doing this!"