Three things mildly irk me:
One, expressions of surprise over the death of elderly and largely inactive celebrities.
Two, shallow discussions of recently deceased celebrities on blogs.
Three, lists of things that annoy a blogger.
While we're at it, let's go ahead and make it two for three.
Arthur C. Clarke was my introduction to science fiction, although not through 2001 or some of his better known books. I read Hammer of God when I was 12, very near to it originally coming out and immediately before picking up William Gibson's Neuromancer. I liked the book but fell more quickly in love with Gibson's gritty dystopia, which for a young man just entering his teen years is unsurprising.
At the time I wasn't aware that Clarke had lived through a time when science fiction grew out of the realm of fantasy and into thought experiment, and that his contributions to the world of science in some ways outweighed those to literature. It wasn't until college that I read Childhood's End and 2001 and realized how thought provoking a well written work of sci fi can be.
I count him among one of the authors who have had the most influence on my life. He will be sorely missed.