Bach's Mass in B Minor: What is best CD out there?

The Gardiner is a light "original instruments" like sound.
It is very good if this is how you like your Bach.

If you want a more "classical" choral sound, then a recording like the "Robert" Shaw/Atlantic Symphony recording would be a better choice.

Actually my picks on "modern" instruments instead of the Shaw would be.....

Soloists...Auger, Murray, Lipovsek, others...
Leipzig Radio Chorus/Staatskapelle Orchestra, Dresden, conducted by Peter Schreier.
On Philips 432 972-2

Soloist, Marchall, Ramey, Baker, Tear, others...
Academy of St. Martin-in-the-fields/Neville Mariner conductor....
On Philips 416 415-2

If you like an historically informed performance, but find the Gardiner too "light" (as suggested by Sugarbrie and in which I agree), consider the superb performance by Harnoncourt and the Concentus Musicus Wien on Teldec (Elektra/Asylum - #95517).

This is Harnoncourt's first performance of the Mass in b-minor, recorded in 1968. Of the various performances of this work in my collection, this is the recording I keep returning to.

Please forget any recording of this greatest piece on earth and try to get Thomas Hengelbrock conducting the Balthasar Neumann Choir and the Barockorchester Freiburg. It might not be in stock in the US but DO ask for it. When they got to the moon they should be able to get this CD for you!
You won't regret going through any trouble getting it!

If you want the recording Aida_w mentions, and it is not available in the US, then check the UK Tower Records website which is:

http://www.towerrecords.co.uk/

They will ship to the US from the UK store. It is not much more for regular air mail shipping.

I have bought quite a few "unavailable" CDs this way.

The Collegium Vocale under the direction of Philippe Herreweghe come the closest to capturing the beauty and devotional spirit of Bach's choral works. How? Difficult to say exactly, but the fact that Herreweghe combines authentic instrumentation, etheric choral tone, period-sized forces, fine soloists and stately rhythms (no windshield wiper tempi here, as you will hear in the Gardiner) doesn't hurt. The Collegium Vocale/Herreweghe also have quite successfully recorded Bach's Magnificat and Easter Oratorio.