I have done a lot, and I mean a lot of research on classical music, syles, composers, etc.. And my all-time favorite is Sergei Rachmaninov. To me his music in incredible, emotional, powerful, elegant, poetic.. Jean Sibelius comes closely behind, along with Sergei Prokofiev.
I used to like Bach, Mozart and Beethoven. And I still like them. But I feel that late Romanticism music is for me.