SPLAT users, what's your favorite composer? and why?

I will dive in with someone contemporary. Greg Spawton of Big Big Train. The track "Transit of Venus" is one of the best examples of his work. Lyrics, Melody and arrangement are superb. Other band members write some fine stuff but its Greg's songs that stand out for me.

Different eras, different genres I could come up with so many, so difficult to choose.

Don't have just one favorite.  At the moment it might be Debussy, since I just now listened to La Mer.
At various points in my life these have been my favorites:
 
Shostakovich- deep, dramatic, expressing the tragedies and triumphs of Russia
Stravinsky- The Right of Spring, say no more
Tchaikovsky- great symphonic works, immortal melodies
Bartok- Music for Strings, Percussion and Celeste is out of this world!
Mahler- expanded the boundaries of symphonic structure, favorite is Symphony No. 2 "Resurrection" Choral part is breathtaking.
Berlioz- Symphonie Fantastique 
Bach- Brandenburg Concertos
Beethoven- Symphony No. 9
Haydn-  over 100 symphonies
Handel- The Messiah and his Water Music
Mozart- Symphonies, operas, choral and chamber works
Ravel- Bolero, and his tremendous orchestrations of Mussorgsky's Pictures at an Exhibition and Night on a Bald Mountain
Rimsky-Korsakov- Scheherazade 
 

oh yeah, i forgot about all my jazz influences, miles davis, dizzy gilespie, ray charles, mainly cause i dont play much jazz anymore.....ive fallin heavily into blues rock and **** rock these days....but yeah, good to hear other peoples influences, and yeah, how can i forget frank zappa, and brien wilson......yeah, im influenced by everything really......there is so much out there, even local musians who will possibly never really ever get recognised or heard by the masses........and i do have one of those, inspired me to learn guitar in high school, the guy just oozed soul on his guitar......i heard him again at a party recently, 25 years later, he still has something that i just cant reach.......and most people will never hear him play cause he is a family man with no desire to record or even perform.

Okay, since we're talking composers and not songwriters, I'll defer my Paul McCartney suggestion.
Classically speaking, I'm partial to Beethoven, then #2 Gustav Mahler . . . they captured the most extreme ranges of emotion in their respective eras. More recently, it has to be John Williams . . . because his amazing range of music for film in the contemporary era is bound to be classical 100 years from now.

Are songwriters not composers?  What is the distinction? Its all music, just different styles and types.
 
Frank Zappa would embody both since he wrote songs and so called "serious music", a term he himself hated. So is he a composer when writing one type of music and a songwriter the next, and if so when does it change?  Keep it simple and call them all composers.
 
Anyway, cant really call them favorites because the list is almost endless. I like so much different stuff. 
Bartok, John Williams[<font]. Bill Evans, EST, Jaga Jazzist, Mats & Morgan, 80s metal/rock, Springsteen, keith Jarret, Warren Zevon, Ennio Morricone, Frank Zappa, Calvero, Radiohead, etc etc etc forever and ever :) 
 
There is good music in every genre I am sure, just  matter of finding the good stuff.