You can only take 5 albums to a deserted Island...

And I'm thinking Ginger, Mary Ann and I will dance, play, and whatever depending on the mood created by the music you are playing.

Deep Purple - Machine Head
Led Zeppelin - II
Dire Straits - Brother in Arms
ZAZ - Recto Verso
Pink Floyd - The Division Bell

Once we all get to the Desert Island, this island will be nicely stuffed with music!!!    :-)
DANVIGNAU, thank you for flushing PF fans out of the closet, because I was a bit worried what is happening here. So, while we all On The Island, here is the list of my 5 Must-Haves which I see missing from the collection:
1) Tchaikovsky's 5th under Mravinsky
2) Bruckner's 8th under Celibidache
3) Dead Can Dance box set
4) Cocteau Twins box set
5) Klaus Schulze Mini-LP CD box set
Some other painful (for me) omissions on this thread here are:
6) Porcupine Tree
7) quite a few must have or "We Must Die" from ECM label, starting with "Khmer".  Those who ever loved Miles must give it a listen!
8) Tubular Bells (!!!)

Gotta have some variation for my 5:

1)  Pink Floyd - Dark Side of the Moon
2)  Norah Jones - Wish You Were Here
3)  Miles David - Kind of Blue
4)  Bach's Cello Suites - Janos Starker 
5)  AC/DC - Back in Black

Ginger and Mary Ann would improve this whole hypothetical scenario thing, as well!