Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Nightmare Fuel: Eminem
The album Encore is not for the faint of heart and isn't the best music to sleep to. (But then again, why the fuck would you sleep to Eminem anyway?) The last track closes with Eminem shooting his crowd and killing himself. A robotic voice ends the album saying, "See you in hell, fuckers."
Probably a more down-to-earth example than most of these, but you may die a little inside after listening to Slim Shady's "Kim", a song he wrote about killing the woman who was back then his Real Life wife.
The worst part? "There's a four year old little boy layin' dead with a slit throat in YOUR living room". It was so disturbing that the line isn't in any official versions, you can only find it on the internet.
In Real Life, after Kim saw a performance of "Kim" where Eminem yelled at and abused a human-sized doll of her on stage, she attempted suicide.
As far as mainstream rappers go, Eminem is pretty hard to beat when it comes to being disturbing. On the same album as "Kim" we have "Amityville", and "Stan", which is about a deranged, obsessed fan of Eminem's who ultimately drives off a bridge and kills both himself and his pregnant girlfriend, just because his letters to Eminem didn't get answered (the final verse, which features Eminem finally responding to Stan's letters, has a whopper of a Fridge Horror at the very end). Relapse has "Same Song and Dance" which is about kidnapping, raping, torturing and murdering celebrities. Although the song itself isn't bad, "Just Don't Give A Fuck" off The Slim Shady LP has a pretty eerie instrumental.
"Music Box", which is possibly his most outright disturbing song to date. Cannibalism, murder, Satanism, pedophilia, stalking, rape, torture....so many great, wholesome flavors make up this little nightmare anthem.
An MTV Brazil VJ said that watching Cleaning Out My Closet (which features Eminem burying his mother) while pregnant is really unsettling.
"'97 Bonnie And Clyde" (AKA Just the Two of Us). It's one of his most haunting songs, sung from the point of view of a father to his daughter after murdering his wife for infidelity. He has his little daughter help him unload the dead wife from the trunk of his car and dump her corpse in a lake. Then Tori Amos released a cover on her album Strange Little Girls, sung from the murdered wife's point of view, that is somehow even worse.
"Kim", the prequel to "'97 Bonnie & Clyde". The song isn't so much rapped as screamed between Eminem and his impression of Kim. It starts out innocently enough with Em watching Hailie sleep, but quickly goes south as he shoves Kim into a car and reveals he's murdered her new boyfriend and their 4-year-old son (lyrics describing this were actually left off the ''explicit'' version of the album, even though a later reference to the murder was left in; a truly explicit version called "Bitch So Wrong", which keeps the words intact, has been leaked and is still floating around online). It ends with him slitting her throat in the woods:
You were supposed to love me!
Now bleed, bitch, bleed!
BLEED, BITCH, BLEED!
"Stan" is fairly disturbing. It's about an Ax-Crazy fan who eventually commits a murder-suicide because Shady won't answer any of his fan letters in a timely manner. Especially as the tape is starting to end and you can hear Stan's girlfriend screaming from the trunk before the car falls into the water...
"Bad Guy" off of MMLP 2. It has undoubtedly the most evil beat out of any Eminem song, and it samples Insane from Relapse. On top of that, the song is about Matthew (Stan's brother) avenging Stan's death by burying Eminem alive at the bottom of the sea. Then the final verse show up, which is... well, just go check it out for yourself. And this is the first song off the album.