YOU!
There is something in every genre that appeals to me on some level. Film music is my main interest, primarily because it crosses genres. Tan Dun's score for "Hero" is one recent find, but Henry Mancini is hard to beat.
For orchestral music, I think it's hard to beat the Russians: Rimsky-Korsakov, Stravinsky, and Prokofiev are some of my favorites.
In jazz, I'm amazed by Hoagy Carmichael, George and Ira Gershwin, and Jimmy Webb.
Choral music is a love/hate thing for me. Morten Lauridsen and Eric Whitacre are inspirational artists. Orlando Lassus is my old school favorite.
Pop stuff: Ween, Third Eye Blind, Beck, Squirrel Nut Zippers, Metallica, Leo Kottke and more...
When I write, I go with what I'm feeling. If I don't have much to say, then I don't bother picking up the pencil. My most recent composition is a brass quintet.
As many as possible. My father sells them, so I'm always getting recommendations on good reads.