Least depressing portion of Madoka Magica
is the ED, Magia by Kalafina.
“Why not the OPening?” you argue.
Because the OP is a freakin’ hell of a troll, if I’ve ever seen one. Which makes it depressing also, especially if you’re expecting a healing anime on qute wittle magical girls hopping around banishing ebil witches.
And because Kalafina is just pure awesome, I say.