I finally found a piece by Benjamin Britten (and I’ve listened to a lot, so whatever you’re going to recommend, I’ve probably heard it) that I’m enthusiastic about, a chamber piece called Young Apollo. Here’s what Grove has to say about it:
Young Apollo, written in summer 1939 for a CBC broadcast with the composer as piano soloist, was inspired not only by the last lines of Keats’s Hyperion but also by [former lover Wullf] Scherchen; originally designated op.16, it was withdrawn and not heard again until after Britten died, either because of the personal association, or (more likely) because of its dependence, musically, on an elaboration of the A major triad, a kind of musical minimalism that was not the order of the day.
I have this experience all the time with “famous” (orchestra-circuit) living composers: find one piece I like, compliment it, and of course it’s the one they’re ashamed of.