This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Black Flag
"Damaged I" initially started as your typical title track off of a seminal punk recording, until Greg Ginn decided that the backing track be played at a slower tempo to suit Henry Rollins' vocals, making the final result, well, upsetting to say the least.
"Armageddon Man," off of Family Man, and "I Can See You," which could very easily be a candidate for one of the creepiest songs of all time, both musically and lyrically.
The entire second side of My War seemed designed to outdo the claustrophobic sludge of the Damaged version of "Damaged 1", as it featured three incredibly slow, heavy songs, each clocking in at over 6 minutes. YMMV on how effective it was, but the songs featured some particularly feral Rollins screams and guitar leads that were atonal even compared to Gregg Ginn's normal playing style.