What is/are your the most favourite composer s ?

John,
I'm also checkin' on that actually. Not too many music lovers know that there are quite a few composers that are alive and create a great music different from 100+ years ago but still you can realize the craftsmanship and standards opposing an improvisation and rather having a strict structure similar to a few centuries ago...
A few more living ones: Michael Nyman -- Check out "The Cook the Thief, His Wife and Her Lover" soundtrack and many more of his works...
Philip Glass; John Lurie for movie soundtracks; Roger Eno for his amazing solo piano works, H.J. Roedelius goes along...

Seems to be a real dearth of French composers here. How about Rameau, Couperin and Lully for Baroque? Also a fan of Henry Purcell, Ralph Vaughn Williams and Schubert.
BTW: I attended a solo recital by Astor Piazzolla on bandoneon.

In the spirit of your post, blasting song after song I would add to many of the above a few 20th century composers of popular music much of which is timeless.

George Gershwin
Duke Ellington
Antonio Carlos (Tom) Jobim
Richard Rodgers

My top 15 
BACH
Josquin Desprez
Mozart
Schubert
Brahms
Purcell
Puccini
Palestrina
Haydn
Janacek
Telemann
Sibelius
Richard Strauss
Byrd
Vaughn Williams