I can understand how people can say Orlando and Viggo, because not only are they incredibly hott, but take a look at how much they've put into their acting - learning to use swords and bows like that isn't easy, and it should take years to learn. However, I chose Frodo. I'm not just saying that because he's the best-looking person I've ever seen, though that does count for something.
Have you ever looked at how much Elijah Wood acts through his eyes? Take any Frodo pic. Cover the eyes with your hand. You'd never be able to tell what he's feeling that way - his mouth is always the same. Now cover the bottom half of his face and look at his eyes. You can tell EXACTLY what's going on (this works even better on pictures where he's scared - I'll post one at the bottom.). That deserves to be commented on - I have never seen another actor act through his eyes like that...