On Lisp and ANSI Common Lisp are still relevant in regard to their subject matter while the essays of Hackers and Painters can at times seem dated despite being more recent. That's not to say that Graham's essays haven't had more impact, it is possible they have.
But even the essays when presented in book form seem to hold a greater claim upon us than a dozen or so links in an email or blog post. Then again I don't deny my bookishness.
An opinion column in a well respected publication has the ability to wield more influence. Books are hit or miss and ephemeral.