Mike's the author of the award-winning science fiction novel Eifelheim, which was a wonderfully entertaining and interesting book. I particularly appreciated portrayal and explanations of medieval Christian beliefs and reasoning. Oddly enough, I was reading his blog long before I realized he was an author. It was strange to realize that this random guy on the internet who's writing I appreciated was the same guy who wrote the novel I had just finished.
While there are many SF and fantasy authors that I think I'd enjoy chatting with (or arguing vehemently with, in some cases), Mike's definitely moving himself to the top of the "genuinely interesting and charming persons" list.
Postscript: I wanted to check my facts before commenting further... and indeed, Mr. Flynn is a fellow Pennsylvanian. It's a big state, so I can hardly claim that he's a neighbor. Despite that, I can be happy that this geographic coincidence (ever so slightly) increases the chances of someday being able to enjoy his company around a campfire some lazy summer evening.