So I kinda bumbled my way into this while building my current fortress:
I originally built it as somewhere to show off my useless "finished goods" artifacts as well as some of the better artifact furniture until a noble came along. After a while I put in a couple of cages with some exotic wildlife the
walking firelighters elves brought with them and made the thing a zoo.
What I didn't realize was the
massive happiness boost my dwarfs get from just spending even a couple of seconds in there. They admire the cages, the animals in the cages, the sublime windows, the doors coming in and the artifact furniture. I'm going to chuck in a couple of traps with masterful gears and weapons next for the "admired a tastefully arranged trap lately" thought. And to top off all that, my dwarfs have to walk through a mist generator (specifically, this mist generator
http://www.dwarffortresswiki.net/index.php/Mist) to get to the museum. You gotta be careful though, as making the museum with a large floor space, which was the predecessor to this design in another fortress, waters down the number of happy thoughts as a dwarf just doesn't move close enough to everything to admire it.
This massive number of good thoughts has so far seen to it that pretty much everyone of my dwarfs are still ecstatic through a minor magma flood, a major magma flood (ugh), the first tryout of my defense system (double ugh) and accidentally breaching a chasm right on to the level with a GCS (triple ugh with a good helping of facepalm). It just works so damn well I though I should share the layout.
*Edit* Duuuhhhh, I can good use HTML.