I saw both.
Narnia left me vaguely unsatisfied. It did a credible job of telling the story but it didn't really capture the magic. I'm glad I saw it on the big screen, but I doubt I'll want to see it again.
Kong, on the other hand, kicked my butt in a big way. I was hooked from the very beginning and the time just flew by. And, Good Lord, if you're gonna see it don't wait until it comes out on DVD. It thrives on the big screen.
As far as pathos goes (and both movies go for the pathos pretty hard) Kong wins out. I was blubbering like a baby during the whole New York scene. He was so lost, so afraid, and so REAL.