Had to think about this one for a while... Anyway, the albums I wouldn't like to be without are (in no particular order, and limiting myself to one per artist):

1) Pink Floyd - Dark Side Of The Moon
2) John Cale - Fragments Of A Rainy Season
3) Tom Waits - Bone Machine
4) Lou Reed - New York
5) Miles Davis - Kind Of Blue
6) Giant Sand - Selections Circa 1990 - 2000
7) Radiohead - OK Computer
8) Steely Dan - Aja
9) Bob Dylan - Blood On The Tracks
10) U2 - Joshua Tree

Fighting for space (frequent listens and recent interests) would be:
John Cale - Paris 1919, Fear
Pink Floyd - Wish You Were Here, Animals
Tom Waits - Raindogs, Closing Time
Laurie Anderson - Bright Red, Strange Angels, Life On A String
Radiohead - The Bends, Amnesiac
Manic Street Preachers - The Holy Bible, Everything Must Go
Neil Young - Rust Never Sleeps, Ragged Glory, Zuma
Lou Reed - Transformer, Perfect Night, Berlin
The Band - Music From Big Pink, The Band
Steely Dan - Can't Buy A Thrill, Pretzel Logic
Giant Sand - Centre Of The Universe, Glum, Chore Of Enchantment
Wynton Marsalis Septet - "In This House, On This Morning"
John Coltrane - A Love Supreme
Miles Davis - Sketches Of Spain

(and probably many, many more...)

I thnk this list probably mirrors the order in which I loaded my empeg...
Bryan.