In some vague order;

Tchaikovsky
Mozart
Beethoven
Debussy
Dvořák

At the moment:

Mozart
Stravinsky
Glass
Mahler
Holst

Finally somebody puts Prokofiev on a list!

Thank you

Brahms (Requiem, the symphonies, the concert pieces with vocal and chorus)

Beethoven (the symphonies, piano concertos and sonatas, the Masses)

Mahler (sym 1, 3, 5, 6, 9, The Song of the Earth)

Ives (Central Park, Unanswered question, Gong hook and ladder (sic) etc.)

Bach (sonatas, partitas and suites for violin and cello, piano preludes and fugues)

Sure I'll go with that from the hip.

1. Mozart
2. Bach
3. Irving Berlin
4. Toto
5. Beethoven

edit: Tchaikovsky was ***.
edit: That's censored? Odd, it's not an insult, just a fact.

Rachmaninoff
Shostakovich
Bach
Liszt
Bartok

Messiaen
Bartok
Mahler
Beethoven
Debussy

Johann Sebastian Bach
Ludwig van Beethoven
Pyotr Tchaikovsky
Antonín Dvořák
Sir Edward Elgar

1. Beethoven (Symphonies are phenomenal)
2. Chopin (Piano FTW)
3. Liszt (SHOW OFF)
4. Rachmaninov (Solely for his Piano Concerti)
5. Brahms (Symphonies and Piano Concerti)

1. Beethoven
2. Prokofiev
3. Saint-Saens
4. Shostakovich
5. Wagner

The first two are certain, the others may move around and drop out as time goes on.