I have most of SoundChris's suggestions and can recommend them all. The only one on his list that I don't own is the one from Premier Sound Factory.
For BFD, there is a collection for Taiko and another for Kabuki & Noh Theatre. I'm weaning myself off BFD stuff as I've recently switched to Superior Drummer for my main drum workflow and to non-drum hosts for percussion work, so shoot me a PM if interested in those. They're both pretty deep and dry, and take a different approach from other libraries that cover that material.
Actually, I think Sonica (mentioned by Lode-Runner above) is the one who produced those two BFD expansions (I'll check later, and also see if they've done other stuff besides those two). There are also pattern libraries available for them.
For melodic instruments, it is still mostly a piecemeal affair. I'll check my sound source list a bit later to see if I have anything else listed that hasn't been covered so far, but I think the early mentions (Tarilonte primarily) and SoundChris's list cover most of the top-end stuff available.
Ethno World is better than it was, but due to several generations and no improvements on earlier material, it's hit-or-miss with each instrument based on when it was introduced to the library.
The UVI overhaul of World Suite (formerly World Traditions, and almost the same library as MOTU Ethno v2 combined with Spirit of Gongs), is a third-generation product that adds lots of new material but also actually improved the older material so that it is overall a fairly consistent library, and it also does a better job than most of the catch-alls of covering actual real-life playing techniques. I'm actually using it quite a bit; more than any of the other "big libraries".
RA is awful; poorly recorded and glitchy. But I still have to use it for a few rare instruments that no one else has done yet. Silk doesn't seem as good as other options for anything where I have something to compare against, and also seems problematic from a phrasing point of view (since I aim for actual realism and authenticity vs. "flavour of the month" colouring of the sonic background), but it still has a few options that may be unique to that library.
Don't forget Garritan World, which often goes on sale. I bought it for $40 as I recall, primarily for its user manual, which is the best ethnomusicological background sheet I've ever seen that helps me to be aware of what is out there (though nothing is truly complete) and to better understand the differences between instruments that are often mislabeled, such as afuche vs. shekere vs. cabaca.
I'm sure I'll hit upon others when I consult my thorough sound sources document that I have maintained and expanded over the years. I don't always bother annotating all the huge orchestral percussion libraries though. Or stuff like Spitfire Labs, which might include some of the desired instruments (if so, most likely middle east stuff).
Speaking of which, there are indeed some very well done Asian wind instruments by Spitfire, in Andy Finton's Kitbag, and Soundiron has a few libraries as well (though their stuff can be a bit uneven in quality and depth).