I love the sound of the Anglican cathedral choirs.  Never fail to attend "Evensong" when in England. 

My favourite is the choir of the Chapel Royal in Hampton Court Palace - excellent and underrated.

Cambridge Singers?

Rheinberger "Abendlied", sung by the Cambridge Singers

Versa est in luctum (Lobo) - Hogan Ensemble

Eric Whitacre Singers perform the composer's "Alleluia"