The barrow downs chapter, OTOH, is pretty good - used to really give me the creeps (though not as badly as the mines of Moria or Sheldon's lair).
Thinking of Shelob, and in geek mode again, someone pointed out a really funny "continuity error" in the books. Frodo has learned Elvish from Bilbo. Men of Gondor speak a form of Elvish as their native language. So in fact the conversation between Faramir and Frodo actually reads:
"Don't go up the stairs of the tower of the giant spider, Frodo."
"Why, what's at the top of the stairs of the giant spider?"
"Who knows, Frodo, who know."