Your Ultimate Reference Recording

What do use as your ultimate reference recording?

Through the many years of collecting music and building a music library, I have purchased certain LPs or CDs that have excelled in recording and sonic quality. These ultimately became the recordings I have come to use for auditioning audio gear, A/B comparisons and/or demos. They have become my reference recordings.

Repeated playing of these reference recordings on different systems have taught me all of the details and nuances of these recordings creating a standard to use as a basis for comparison. I would be interested in knowing what other people use as their "ultimate reference recording".

I think this post could be a great exchange and a broad exposure to super quality recordings others may be unaware of. In your response, please note whether the recording is in LP or CD format. If you have an LP reference and a different CD reference, please list both.

My ultimate references are:
Patricia Barber/ Cafe Blue-CD
Dave Grusin/ Discovered Again-LP (Sheffield, first issue)

Thanks for responding.