Sometimes I put William Byrd's Domine secundum actum meum, on "repeat". I never grow tired of it. This version is sung by David Hobson on the Elizabeth soundtrack, where it is titled "Night of the Long Knives".
Domine secundum actum meum noli me
indicare nihil dignum in conspectu tuo egi.
Ideo deprecor maiestatem tuam, ut tu,
Deus deleas, iniquitatem, meam.
Lord judge me not according to my deeds, for I
have done nothing worthy in thy sight.
Therefore I entreat thy majesty, that thou,
O God, would blot out my iniquity.