Mine would be:~
The journal you see Bilbo and Frodo writing in ...
"There and Back Again, A Hobbit's Tale by Bilbo Baggins."(I'm not sure if Peter Jackson meant that to be the Red Book of Westmarch or not?)
The One Ring
Frodo's Elven Cloak
Hadhafang (looked
gorgeous when I saw it at the Science Museum in London!)
Sting (ditto above)
Leggy's bow, quiver and arrows (sorry Jo if you'd got first dibs on those .... I'll share!

)
Any of the maps .....
Enough length of material used in Galadriel's white dress to make a garment for myself ... it was
stunning at the Science Museum!
The Helm of Sauron
Oh .... and I'll fight Mr Jackson for Bag End to be re-constructed in my back garden!

Hee Hee .... don't want much do I? LOL

Seriously though,
anything would suit me from the set
