Gustav Mahler is my absolute favorite. There's absolutely no discussion.
For the power, the heart, the passion, the kind heartedness he displays, all of them without any arrogance whatsoever. There's no hesitation either in him to visit the dark realms of life, only to come back stronger.
I enjoy Mahler as well. His second symphony is my favorite. Some of the melodies used in that work are from his childhood and you get the impression that they haunted him. His compositions are deeply emotional and resonate with me as an INFJ, but he didn't strike me as an INFJ in a biography I read. He seemed more NT than NF. I was hoping for a kindred spirit.
I read that he was fond of Dostoevsky's work, which was really funny because before I came across this information, I would always say that Mahler was Dostoevsky put in music...
I remember reading a biography on Mahler and of his disappointment in his visit to Russia. He was eager to discuss Dostoevsky and discovered that the average Russian did not share his passion. He also found Russia to be cold. I think that was the extent of the biography's treatment of his visit in Russia.
On the opposite, I can't stand Wagner.
I can respect his techniques and what he did for opera (especially with Norse mythology), but I never found his music to be stirring. Besides, I can't listen to Flight of the Valkyries without thinking of the flying toasters from the classic After Dark screen savers. I've played some of Wagner. I just can't get into it.
To the OP:
I also like these works:
Samuel Barber (Essay for Orchestra no. 2 is deeply passionate, and probably my favorite piece)
Gershwin (I love his harmonies)
Copland's The Promise of Living - but his symphonies are BORING.
Hart and Rogers' My Funny Valentine can get to me.
Beethoven's 7th Symphony, 2nd movement: how can such a simple rhythm be filled with such complexity and emotion?
Elgar's Enigma Variations, Nimrod
As for perceiving a symphonic work, I actually like what Smalin does below to Beethoven's 7th symphony. I enjoy reading scores, but this just seems like the perfect way to actually see the music that you hear:
edit: I have no idea what animal I would liken myself to. I love red pandas, but that would be what I'd like to be, rather than what I am. A better choice for me would be the panda bear - not the stuffed cuddly kind, but the real animal. The public seems to like them, but they don't really know much about them. They are choosy about mates, and appear to be rather peaceful creatures. However, they are powerful and can be angered. I also think bamboo is fascinating.