A friend is asking about English-language librettos(i) with better
literary/dramaturgical merits.  There are certainly the Britten operas
to suggest: Billy Budd, Peter Grimes,...

I guess it's useless to impose limitations on how far
you can go on this list; but preferrably:

1.  those that were originally written in English, but can be adaptations
from a foreign language source.
2.  those that were specifically intended for an opera production.
3.  please note the question asks for literary/dramaturgical merits which
include (certainly not limited to) poetry, structure, characterisation,
action, spectacle(!)...  So it doesn't matter how lousy the music sounds!
4.  the more recent ones, the better.  (Sadly, I find myself extremely
ignorant in American operas.  Why not take advantage of this opportunity to
learn something?)

Thanks in advance.

Vachnadze