Believe it or not, I find VSL Solo Strings to be magnificent across ALL genres, and keep coming back to them and regretting other purchases (selling when allowed). So expressive and human! Gorgeous timbre, rich, deep, and it is so easy to apply them to Klezmer, jazz, etc. due to the many expressive articulations available. I have tried MANY other libraries, and nothing comes close! I have not yet given the new Sample Modeling Strings a full fair shake yet though, as I am so far along in my projects with the VSL Solo Strings.
The VSL Upright Bass remains the only one that I like for Jazz and other genres, period! And I have owned several dozen over time. A few others have nice articulation and timbre, but none seem to work as well when it comes to phrasing, and also I usually need those lower notes that only a couple of other libraries provide.
Don't forget that most Brasilian styles use nbylon string guitars, and I find the VSL Concert Guitar ideal.
I've been using Sample Modeling for Trumpet and Trombone (as well as Horn and Tuba), but hope to spend some time soon, with detailed artioculation mappings of VSL to see if I can match the naturalness of my existing tracks. There's a lot of idiosyncratic playing involved, and I haven't yet checked to see whether VSL is too "baked-in" as is Chris Hein Horns (otherwise a great library as well, and not to be confused with their orchestral libraries).
Note that I am referring to many different non-Orchestral contexts here: Jazz, Samba, Bossa, Salsa, Klezmer, Pop, even Rock, R&B, Reggae, Ska, Dub, Calypso, etc.
It would take me more time than I care to take right before dinner, to itemize my recommendations for Latin Percussion and the like, as it gets spread across many libraries by now -- after two decades of deep experience with MANY products. But without hesitation I have to recommend Hand Held Sound's Flying Hand Percussion for Congas, as it is the ONLY library to fully model all the nuances of hand motions.
NI Discovery Series Cuba took a while to learn deeply and to configure to my liking (easy once understood), but is my current go-to for a lot of other stuff (Bongos, Timbales, etc.), usually with five unique choices per instrument (different models mostly, but sometimes just different head tuning). Other latin stuff crosses many products and vendors.
I have done some pro recording sessions on my bass guitar, for country music, but otherwise don't have enough experience on other instruments in that genre to feel safe with specific recommendations. I do own Bolder Sound Fiddle and it might perhaps work better in that genre than VSL Solo Violin, as also might Sample Modeling's new Strings library (which I prefer to the SWAM stuff by now). Mostly due to timbre, as country fiddle timbre is a bit different from Jazz, Classical, or even Celtic. But there's also VSL's Violin 2 patch, added somewhat recently.
Bolder Sounds Bluegrass Banjo is pretty hard to beat. He also has an interesting fretless gut-string banjo library. Similarly for his Pure Mandolin library.
For piano, I pretty much use Synchron Pianos at this point and have phased out most of my others (where resale is allowed) excxept for the C. Bechstein grand, which is very versatile and flexible. My recollection is that I am using the Synchron Bluethner for Salsa and other island genres; I posted some presets here in 2019. Sometimes the Boesendorfer Upright, or even the more traditional D-274. I'll use Wavesfactory Mercury for the Fazioli sound also.
