The
complete Gesualdo madrigals with Delitiae Musicae dir. Marco Longhini (7 CD box). Very likely the best complete set at any price, AND the booklet includes full texts with facing English translations (not to be taken for granted in this repertoire, especially from a budget label).
The same team's
complete Monteverdi madrigals box is similar and is similarly equipped with texts & translations, but Monteverdi is a much more crowded field and it would be a brave soul who would nominate a front runner!
Brahms Four Hand Piano Music (18 separate CDs) with Silke-Thora Matthies & Christian Köhn; excellent reviews. I wouldn't place them above all others in the Hungarian Dances or Haydn Variations, but if you want to hear Brahms's own 4-hand versions of his symphonies, concertos, & chamber music, I doubt whether you'll ever hear them done better.
The two
Saint-Saens String Quartets played by the Fine Arts Quartet. Consistently strong playing and remarkably vivid recorded sound. I see the same quartet also did a S-S Piano Quartet/Quintet disc with Ortiz, which might well have similar merits.
Joseph Marx, Orchestral Works cond. Sloane (formerly on ASV; much admired). Hopelessly out-of-date in style (but so, in his day, was JSBach); composed 1920 going on 1850. Sample vol. 1 (the Nature Trilogy).
Superb recordings. One word of caution: the Naxos recording of Symphony No. 8 preserves a preliminary version of the symphony, three movements shorter than the final version (which can be found on Dux cond. composer).
I've noticed that several reviews of the new Paavo Järvi set of Schmidt's symphonies explicitly judge Sinaisky still the best of all.
For something further off the beaten track,
Maurice Greene's 1739 song-cycle of
Spenser's Amoretti for tenor, harpsichord, and theorbo. Settings of 25 of the best English love sonnets ever written, constantly attentive to the words and musically felicitous, sung by a secure, light tenor with excellent diction (Benjamin Hulett). Can't imagine it done better.