Well, no one can really tell you what you'll like or not, thus it's a bit pointless to start naming pieces you might like.
On the other hand, I'll just post a few pieces that I personally love (just a short list on top of my head):
Schoenberg's "
Verklarte Nacht", Op.11
Webern's "
Langsamer Satz", Op. Post.
Mozart's "
Vesperae de Dominica"
Debussy's
String Quartet in G minor (Op.10), first movement
Anything by Feldman (although I assume you'll get bored really quickly by Feldman

)
Takemitsu's piano pieces (I love his
Romance,
Litany and
Rain Sketches), and his piano and string works, like
Hika and
From Far Beyond Chrysanthemums and November Fog
Ligeti's
1st String Quartet, and his
Etude No.13 for piano ("
The Devil's Staircase", I think)
Ives' "
Feldeinsamkeit" (one of my favourite songs ever)
Carl Vine's "
5 Bagatelles" (the fifth one is incredibly beautiful)
Birtwistle's "
Tragoedia" (especially the 5th movement)
Paul Newland's "
Standing Jump" (incredible piece)
So there

If I remember of anything more, I'll let you know

Please let me know which ones of these you liked and which ones you didn't, so I can suggest more
