This thread reminds me of this:
http://en.wikipedia.org/wiki/Cabinet_of_curiositiesIt's a reasonably interesting read on how museums, as we know them today, got started.
I'd very much like to have more display options. Displaying Artifacts, ornate and unusual masterworks, valuable bones/gems/specimens, etc. would be a great tool for not only constructing "museum" type rooms, but for enhancing any part of the Fortress that might seem to need it.
Dwarfs might get happy thoughts by admiring such things, particularly if the displays contained items they liked: "Urist McCurious was ecstatic lately, she visited the Great Olivinarium recently, she admired a legendary collection of olivine mugs recently, she admired a legendary collection of olivine thrones recently, she admired a legendary collection of olivine statues recently..."
Having a specificly denoted collection of rock-samples, for that matter, with olivine being one of those specimens, might be enough by itself to turn Urist on a little.
And such happy thought generators wouldn't necessarily have to be placed in the dining room, or the dwarf's personal quarters, to be useful. You might simply put them in an otherwise uninteresting hallway, or an otherwise dull storage room.
Infact, this might actually make the storage of items itself (and how dull is storage, anyway?) an exciting proposition.
Having these museums around to provide education and experience, might also possibly cause your Fortress's children to grow to adults a little faster.