I first read The Hobbit when I was about 10. A while back it occured to me (probably while watching the last slice of Peter Jackson CGI) that I had never reread it. Finding an nice Allen and Unwin edition (see above) in a charity shop a few weeks ago pushed me over the edge.
The first thing I noticed was how good Tolkien is at landscapes. This is a story with many changes of scene, and in a way the landscape of Middle Earth is the subject. There is a sense of real observation in his descriptions: they are not generic. The approach to Rivendell made little sense to me as a child:
They were growing anxious, for they saw now that the house might be hidden almost anywhere between them and the mountains.
How can you lose a valley? But after walking in the Alps I can believe the sudden transition:
They came to the edge of a steep fall in the ground so suddenly that Gandalf's horse nearly slipped down the slope.
Likewise, where our heroes are trying to get away from the Misty Mountains they slide down a steep slope of loose rock debris and are saved by the pines on the fringes of a wood. This reminds me irresistably of parts of the Cairngorms.
If the journey struck me strongly, the supposed excuse for it (lost treasure, the Lonely Mountain etc.) takes a long time to arrive and is dealt with rather speedily when it does. However if the climactic battle is briefly described, ex-Lieutenant Tolkien knows what he is talking about.
The book is also the journey of Bilbo from timidity to responsibility. I notice that a key scene where he takes charge of a difficult river crossing is at the exact midpoint of the book. I've no idea if this is deliberate or not.
I'm sure I will end up watching the third part of Peter Jackson's film version. Given what I've said, it may be no error for him to take so long over the journey. But the meaning for me is in the reality of the landscape and not in a lot of fantasy violence made with an eye for a video-game spin-off.