Contemporary composers. Please help.

Poulenc, Del Tredici (Final Alice), Bernstein, Prokofiev, Elgar, Sibelius, Menotti. . . among others previous mentioned.

Wow!!! Thank you guys! Thanks for such a great response.
I'll try to pick as many as I can. Some titles I aready have, so if you guys don't mind, I'm going to share some impressions to more properly defy my sphere of interest at this moment.

Thanks again.
Sergey

I'd like to mention Britten's string quartets. This maybe heresy, but I prefer them over Bartok's quartets. I like the Belcea Quartet's recording of these works. Also, check out Jennifer Higdon's piano trio and look for her violin concerto for which she won a Pulitzer today I've been told. I heard this work premiered by Hilary Hahn in Indianapolis and it is a very worthwhile piece of music.

If you like Reich you might try the tonal minimalists such as Niblock, Tenny, Palestine, and Lucier. If you like 12 tone try Webern, Schifrin, and maybe even Verese. Also try Zorn, Cage, and most importantly MORTON FELDMAN if you like Part especially.

In addition to the good recommendations already listed I'll add Robert Simpson.