We are big fans of making 3D puzzles. We have all of the Lord of The Rings puzzles and I've created 2 of them so far.
Orthanc - we tried this one and it hurt our heads because the pieces were mostly black with little white/gray/silver slits in them. One day when I'm really bored and the Internet is having a slow day and none of the people I follow on Twitter/Blogs are posting anything exciting and I don't have to organize my closet, I'll come back to it.
Hobbiton - completed
Meduseld aka The Golden Hall of Edoras - completed
The Citadel of Minas Tirith - have never opened this one, but I might soon, I want to start it.
I picked up The Curse of the Black Pearl 3D puzzle for Mike a few years ago, but it took me to start and finish it, except with Mike hovering around trying to sneak in a piece and take credit for it.
Gimli was not impressed when I spent a great deal of time fussing over pieces instead of playing "I-throw-the-toy-Gimli-grabs-it-but-doesn't-give-it-back-to-me."
Instead, when I showed Gimli my hard work, this is what he did.
Can you imagine a corgi-monster? Think of the appetite it would have!