favourites:
Smetana - Ma Vlast
Shostakovitch - any
Charles Ives - 3 places in New England
Schoenberg - Verklarte Nacht
Zappa - The Yellow Shark
that's in order of increasing disorder
generally, Eastern European or Russian and music that flirts with melody but sometimes just goes crazy ... I am currently experimenting with Stockhausen and want to try Edgar Varese because Zappa liked him.
opera I haven't really got into, though "Nixon in China" by John Adams is ok