What sends shivers down your spine when you play it on your system?

Horrors!  Yes, typo, Mahler 5.  Must proof-read more carefully...
@newbee  If you don't already have it, the 2CD expanded version of Live at Blues Alley entitled Nightbird, to me sounds even better than the original release, plus there's a bunch of additional material. 

mapman,
My first choice is Hugh Beam with Boult, the original conductor ." The Essential Vaughan Williams" on Warner classic

Very close is the great Scottish violinist  (never mind her name} Nicola Benedetti with Andrew Litton - forget the label but easy to find .

Iona Brown with Neville Marriner on Argo is also a heart breaker .

Dream Brother - Jeff Buckley
Satellites Lost - Delays
Musical Box - Genesis
Ana - Pixies
Black Flame - Renaissance
Two Step - Throwing Muses

+1 Balled of Dwight Fry

Star Wars Main theme Performed by the London Symphony orchestra & conducted by John Williams.

The 1st movement of Mahler 9.
Rachmaninoff “The Bells” 1st and 2nd movements (I have about 20 different versions of the piece.)
Brahms Cello Sonata #2, 4th movement.
Schubert Piano Sonata in Bb. D.960. (And much other Schubert.)
Anything by Eva Cassidy (Can’t help but tear up when she sings.)