At dinner last night, my sister-in-law mentioned that she believes most LDS woman have a crush on President Uchdorf. I can see that. He's tall, good-looking, has a wonderful German accent (who know how many languages he speaks?), flies planes, and probably looked great in his uniform as a commercial airline pilot. And there's no denying that he is a powerful speaker.
However, my favorite living general authority speaker is President Eyring, although I must admit that he doesn't have the same, umm, physical draw as President Uchdorf. (In case you're wondering, my all-time favorite was Neal A. Maxwell.)
Now, I'm sure that what the creators of this challenge were looking for was someone more commercially celebrated. So in that case, I guess I have to say that it's Nathan Fillion. He's just shiny, cap'n.