Linkin Park - My December ;0
Linkin Park - Crawlin' ekkekeke
The bulk of the music I listen to is depressing in one way or another, but here are some songs that really get to me.
Songs That Make Me Feel Like Crap
The Downward Spiral - Nine Inch Nails
Piggy - Nine Inch Nails
Street Spirit - Radiohead
Climbing Up The Walls - Radiohead
Songs That Put Me On The Brink Of Tears
Feeling Good - Muse
Hurt - Nine Inch Nails
And All That Could Have Been - Nine Inch Nails
Fake Plastic Trees - Radiohead
How To Disappear Completely - Radiohead
Songs That Do Neither, But Lay Somewhere Between
The Frail - Nine Inch Nails
The Day The Whole World Went Away - Nine Inch Nails
Pulk/Pull Revolving Doors - Radiohead
Morning Bell - Radiohead
ADDED: BTW I wouldn't call Tool depressing at all. I like them very much, but they honestly don't make me feel bad at all. Their music is more about rebellion, angst, and how the world is full of shit. They're more likely to put me in a more irritable mood.
ADDED (2): Any of these songs could very well be listened to and put me in a more happy and excitable mood.