I've never encountered a well written business layer. Any advice?

Question

I look around and see some great snippets of code for defining rules, validation, business objects (entities) and the like, but I have to admit to having never seen a great and

Answer 1

It was helpful to me to learn and play with CSLA.Net (if you are a MS guy). I've never implemented a "pure" CSLA application, but have used many of the ideas presented in the architecture.

Your best bet is keep looking for that elusive magic bullet and use the ideas that best fit the problem you are solving. Keep it simple.