Over in this thread some of us spoke disparagingly about the building experience of some of the new castle sets. Blue pointed out that if you go back to some of the classic sets, they also aren't such great building experiences, from our perspective as advanced MOCers. So, that sparks this questions. What official castle sets do you like to build? Not as nostalgia, because they go back to your youth. Not as starting points to modify the official set and make something more advanced. Not as parts packs that have great pieces, figs and accessories, but actual good building experiences.
I can think of three right off.
3739, Blacksmith Shop (Siskind design). To me this was an education in putting together a building, particularly the roofline. That set also sparked off a wave of variations that became almost a fan-subtheme.

10193, Medieval Market Village. This one owed a lot to the Blacksmith Shop, and really could set in an AFOL medieval layout without modification.

9474, Helm's Deep. The Tolkien sets are pretty advanced in general, but I don't have most of them, so I can't comment. But this one was really fun to build, and included a lot of great techniques to make those shapes and the weathered walls.

Anyway, those are mine. How about you?
Bruce