The Lord of the Rings trilogy is my favourite film trilogy as well, @Shadow. The experience of seeing Fellowship at the cinema in 2001 was magical. Having a read the book a number of times now, I did notice the changes though, particularly in the later films. Some of those changes were quite large (Faramir trying to take the ring and Sam turning back being two major ones). For the most part I thought the changes fit the format well and kept the story focused on the ring, but some were overdramatised. Also film was never the ideal format to capture the depth of Tolkien's world. I've always thought a TV series would be a more suitable format (imagine LOTR with a Game of Thrones budget - it could easily be better the movies). The BBC Radio Play was an episodic version of The Lord of the Rings done very well.
I didn't mind that The Hobbit was more than just the story of the book. Adding the Dol Guldur story made sense, although some parts of it (e.g. Thrain) felt forced. Three movies could have worked had there been more character development or story scenes to justify it. There was plenty of material to create the larger story from. The problem was that there wasn't additional story to justify three movies, but rather lots and lots of extra battles. Just from the first two films we saw the battle with the trolls, the battle before entering Rivendell, the battle in the Goblin cave, the battle while riding the barrels, and the battle with Smaug inside Erebor - these were all invented and none were neccessary to advance the plot. The first film was originally intended to finish after the barrels sequence; arguably they would not have needed to cut out any actual plot to keep the story as two films. Had those unnecessary battle scenes been cut, the story could have been told in two films, 3 to 3.5 hours each.
@Atolm Nice to see you posting here as well. I personally feel that if the First Age Tolkien stories are adapted, they should be done in a different style. Those stories were of a darker tone than The Lord of the Rings and belonged to a more mythological era. Perhaps a different colour palette and overall artistic style could be used to differentiate them from Jackson's work.