Erik Pancakes said:
Off the top of my head, from the extended editions of 1 and 2, I'd definitely include:
An Unexpected Journey
- The small "feels like magic" exchange between Bilbo and Gandalf
- Bilbo seeing the Shards of Narsil and talking to Elrond about staying in Rivendell
- Bilbo and Thorin overhearing Gandalf and Elrond talking about the "strain of madness" in Thorin's bloodline
The Desolation of Smaug
- Most of the added Beorn stuff, especially if he's featured more in the EE of Five Armies - of course, since I'd probably cut Dol Guldur and most (or all) of the White Council, I'd cut the Necromancer and Dol Guldur talk from these scenes
- All of the extended Mirkwood scenes, including Gandalf's mention of a "dark enchantment" in the river
- Bilbo vouching for Thorin in Laketown
- The short bit of Bilbo, Balin and Thorin talking about the woods and birds that used to be on the hills by the Mountain
Other than that, I agree that most of the EE additions don't do much to help the film(s), but all of these seem very worthwhile to me, even for a single-film edit. (Plus, Bilbo is in all of these scenes, and is the focus of all except the Beorn and Mirkwood scenes, which, coupled with cutting out a bunch of extraneous crap, helps keep the focus on ... well ... the titular Hobbit.)
Very good I agree those scenes are well worth adding, pacing issues can be put aside a bit with fan edits, just like they were when Jackson started creating the extended editions anyway.
Don't constrain fan edits in ways other than trying to get a cut that is as pure to the book as possible, as that is what I think most people want with theses films.