Can't seem to get enough Count Basie or anyone who sings with his orchestra...Ella, Frank, Tony, Sarah, Billy, etc. The Count also makes some top notch, top quality, recordings. The horns are usually just killer sounding on a good audio system.
And the acoustic instruments on many bluegrass and acoustic music recordings can also sound stellar. Unfortunately, since bluegrass is the poor stepchild of country music, it can be a bit of a challenge to find high quality bluegrass recordings. Many bluegrass groups/artists don't have the money for top notch studio recordings. So they end up with DIY recordings done in someone's basement. Often not very conducive to high quality recordings.