I've always liked Asimov, and I've read a lot of his fiction and non-fiction. I enjoy his writing style; he writes the way I think, with lots of conversation and not much visual description.
I think my first Asimov book was Adding a Dimension, a collection of his science essays. I was maybe 10 years old, looking through the library's children's section, and Adding a Dimension had been misfiled there. I couldn't take it out, but I had my mother take it out for me.