[chalkpie]

There's way too much to list, but the first pieces that come to mind:

Shostakovich: String Quartet No. 8
Ligeti: Requiem

Two great choices - I'll second these. Too much Schnittke to list here as well. +

Shostakovich 11
Vaughan Williams 7
Xenakis - Kraanerg
Varese - Deserts (w/ tape)

 

[chalkpie]

Tapiola - Sibelius.

Been severely addicted to this piece over the past few days.