In some way the most depressing songs I know are from the last two Sentenced albums. Some of the lyrics on those albums have passed that 'ultra depressing' stage and have come out on the other side, where suicide is a liberation instead of the outcome of some sad state.
I mean, it seems these lyrics are expressing the dawning of some kind of revelation that death is a good thing, and a happiness to have found out about this!
Those lyrics are strangely fascinating, yet disturbing. Because, how far into the reaches of your mind do you have to go, to figure this out?