Top 5 songs about death...

[ZERO THEORY]

Metallica "Fade to Black"
The Smiths "Asleep"
Jedi Mind Tricks "Before the Great Collapse"
Immortal Technique "Dance with the Devil"
How to Destroy Angels "A Drowning"

If you don't make it songs purely about death, I can think of some songs that will really fuck you up. Trent and Kurt both have some songs that make strong allusions to suicide that probably shouldn't be listened to if you're feeling depressed or reckless. Maynard has some stuff that's pretty heavy as well, if you don't need explicit material and allegory will work.