What are the "Must have" LP's?


I have recently re-discovered the LP. I listen to Jazz, blues, classical, and some rock. I was curious as to what my fellow audiophiles here on audiogon believe to be the albums that you simply MUST HAVE. As a sub-question, What LP's do you use to show off your system? Since I am just getting started, I have no real opinions yet, but as I become more and more familiar I will post my findings. Thanks.
limabean683
The LP recommendations on Arthur Salvatore's website are a very worthwhile starting point. Arthur includes detailed discussions of each of the LPs he has recommended.
http://www.high-endaudio.com/index_ac.html
THE FOLLOWING ARE FOR DEMONSTRATION USE ONLY...

CHEMICAL BROS...DIG YOUR OWN HOLE
CHRIS ISAAK...FOREVER BLUE
MASSIVE ATTACK...MEZZANINE
PINK FLOYD...DSOTM
MILES DAVIS...BIRTH OF THE COOL
SISTERS OF MERCY...FLOODLANDS
BEETHOVEN...COMPLETE STRING QUARTETS
AIR...EVERBODY HERTZ
PHOTEK...SOLARIS
Wish You Were Hear, Dark Side Of The Moon, Quadraphenia, Sargent Pepper's Lonley Hearts Club Band, Miles Davis's Kind Of Blue...I could go on forever.
Hi there!

Try Eva Cassidy's SONGBIRD album. Her voice will make you melt like butter!