Brahms' "Ein Deutsches Requiem" with Robert Shaw and Atlanta on Telarc is a definitive recording in so many respects - especially with regards to the choral performance. Also, Arleen Augér was one of my very favorite sopranos, and her performance on this recording is IMO one of the highlights of her career.
Oh and the sound quality is typically Telarc - very dynamic and detailled, perhaps a hair on the bright side. I have both the CD and the LP set . . . and I (blasphomer!) prefer the CD. This work has such loud, dynamic passages at the ends of movements, and in mastering the LPs have some noticible dynamic compression applied towards the inner grooves.