It's been a long time since I've read THE HOBBIT. I wasn't one of those who read it in elementary; my father first gave it to me then, but I didn't get into it. Then The Fellowship of the Ring came out and I just had to read the books so I would know how it all turned out. Waiting for the other two movies was not an option. But yes, I started with THE HOBBIT. I loved the books, but I haven't read them again since. I'm not sure why.
The Hobbit: An Unexpected Journey - movie version - contained the two scenes not involving Smaug that I remembered most clearly, the trolls and the riddle game. There were a few things that I knew were absolutely not in the book, such as there being both goblins and orcs. (Also, a necromancer? What?) Other things I've found afterwards were small details in the book expanded to ten minute action sequences. And that makes sense to me - action sequences play even better on the screen than in a novel.
I honestly have no clue why Peter Jackson is turning The Hobbit into a trilogy. I think most of the changes he made worked. This version will tie in tightly to his Lord of the Rings. But while I enjoyed this film, I have no clue how there is enough of THE HOBBIT left to make two more films. But honestly, the man has delivered good films so far, so I am inclined to trust him. I was quite wary of An Unexpected Journey, and then I absolutely loved it.
Jackson has a knack for casting. Even when I knew the faces, they tended to disappear into their roles. I didn't realize Kili was Aiden Turner (Mitchell in Being Human) until the credits rolled. And he's incredibly lucky, because apparently Elijah Wood, Cate Blanchett, and Hugo Weaving haven't aged in ten years. It's uncanny.
Although he adds in scenes to tie The Hobbit more closely to The Lord of the Rings, Jackson's adaptation proves that he understood the difference between the books. This is a funnier movie, and he keeps several of the songs. I am very tempted to buy the soundtrack. I feel sorry for anyone in anyway related to high school band, because I am sure a large number of shows next year will be based on Howard Shore's score. (I can still remember all of The Lord of the Rings shows I sat though in high school. Thankfully my school couldn't afford the popular stuff.)
I did attend a high-frame rate showing. In case you haven't heard, Jackson shot The Hobbit at twice the usual frame rate. Reports so far haven't been glowing. I didn't hate it, but I didn't think it added anything to the movie. (My dad concurs.) It was most noticeable in brightly lit scenes. If you ever watch making of documentaries, it looks like when they show bits of raw footage from angles that weren't used in the final film. As for the 3D, it didn't really add anything either. It's a beautiful film, but not one where things are leaping at you. I highly recommend seeing it on the big screen, but I don't think you'll lose anything by attending an el cheapo 2D showing.
If you were sitting on the fence, I say go for it. You may not enjoy the movie as much as I did, but if you do, you'll regret it if you miss your chance to see An Unexpected Journey in its full theatrical glory.