Um heres the basics dude
17th Century: Lully, Cavalli, Monteverdi, Scarlatti, Rameau
18th Century: Handel, Haydn, Mozart,Gluck,
19th Century: Weber, Rossini, Bellini, Meyerbeer, Berlioz, Wagner, Verdi, Massenet, Gounod, Bizet, Mascagni, Leoncavallo, Richard Strauss, Glinka, Mussorgsky, Rimsky-Korsakov, Tchaikovsky, Borodin, Smetana, Dvorak, Puccini
more recent: Berg, Schoenberg, Birtwistle, Menotti, Barber, Pfitzner, Schreker, Korngold, Orff, Stockhausen, Henze, Debussy, Ravel, Janácek, Britten, Tippett, Walton, Maxwell Davies, Argento.
my favorites personally are haydn puccini debussy cavalli and scarlatti.