Greg Egan and R. A. Lafferty are my newest favorite authors. They are pointedly different from one another, as Egan focuses on hard science and Lafferty essentially wrote tall tales, with very little science. I have read all 7 of Egan's published novels and I'm currently waiting for Zendegi to be published. Egan doesn't write that much, so it's easy to keep up with him.
Lafferty is a bit more complicated. He wrote a lot; more than 30 novels and 200 short stories. What's impressive is that he didn't start writing until he was in his 40s. His first novel, pictured below, was nominated for the Hugo Award:
The above novel features Thomas More as the protagonist, the inventor of utopia.
Both of these authors are not for lazy readers. They either use vocabulary or concepts that will require the use of dictionaries or other supplemental material. Lafferty makes me use the dictionary every 22 seconds, while Egan makes me use a Physics textbook every 22 attoseconds. That's great and it's what I enjoy about reading.
Although a great deal of information can be found about these authors at other sources, I can summarize by writing that Egan is the hardest of hard science fiction writers (read Schild's Ladder if you want proof) and Lafferty is the funniest (read Through Elegant Eyes).