I fear you have taken the literal meaning of the word to degrees not at all intended. Grave of the Fire Flies i've seen, as I have Now and then, Here and there. Agreed, both were brilliant. Depressing crosses over to tragic, heart wrenching, moving, etc. All of these terms have few attributes in common, which "Depressing" afflicts to.
I remember a few series which broke my heart, like Saikano, and another I forgot the name where the main character falls utterly in love with somebody, and she gets killed in an accident. It... was nothing short of depressing watching him fall apart. That description is mad generic sounding, but i'm not going to go in depth for a series i've already watched, and have no interest in seeking again.
Now lets not get into a philosophical debate over this. I'm not looking to win anything, just looking for advice.
X TV is a wonderful example of the kind of series i'm looking for. The music, the story, the action. Ace all around (and the artwork and animation are still some of the best i've seen despite it's creation being 1998, really REALLY recommend it to anybody who has not had the