I tend to go for individual songs rather than cds.

Favourites are:
Victoria: O magnum Mysterium. Motet and Mass. Oxford Camerata.

Byrd: Mass four four and mass for five voices. Oxford Camerata.
Ave Verum Corpus. Sacerdotes Domini. Christ Church Cathedral Choir, Oxford.[my old choir]

Thomas Tomkins. When David Heard, Almighty God The Fountain Of All Wisdom. Cambridge Singers/Oxford Camerata.

John IV of Portugal. Crux Fidelis. Oxford Camerata.

Henry Purcel: Hear My Prayer, O God Thou Art My God.[check out Clare College Choir on youtube]
Thou Knowest Lord The Secrets Of Our Hearts[though not the setting that Clare College Choir sing on youtube]. The more popular one.

Gibbons: This Is The Record Of John.

Could go on!

I direct A Cappella Choirs and we get to sing most of these.