BIONICLE had several, but mostly in web serials and books, so it was up to your imagination to picture them. Still, they were pretty gruesome: for example alternate versions of characters getting frozen and shattered to pieces, experiencing a Portal Cut, and being literally broken to pieces with a warhammer. Makuta in general tended to suffer quite horrible deaths. Some had their armor melted away with a virus, and their "essence" (containing their mind) incinerated. Also in the serials, Ancient got blown to atoms, and another side character, Botar had his internal organs crushed through his armor. Besides the web serials, some more illustrated works also depicted such events. An example is the last comic of '08, which showed Makuta being zapped to dust by a lightning storm. Finally, the death of the ultimate Big Bad, Makuta Teridax himself also fits this trope. While in the comic, it looked like a simple asteroid caught him in the head, blowing a smoking hole into his skull, the illustrated on-line story medium, the Mata Nui Saga depicted the same event in a more violent way: he got pushed into an oncoming planet, and the upper part of his head shattered to pieces.
Interestingly, according to the writer, he originally had a more graphic way of killing off Teridax in mind, which the Story Team finally rejected. This would have involved the hero, Mata Nui tearing his chest open.
Captain Scarlet and the Mysterons has this in spades; the main characters aren't afraid to use guns. There are even a few deaths that are family-unfriendly simply because of the implications.
For example, a plane full of people is forced to crash in the ocean in the second episode. It gets worse when a duplicate of the plane was used in a successful assassination of a world leader.
In the first episode, the original, full human Captain Scarlet is killed and then the Mysteron version is shot and falls off of a huge viewing platform, screaming as he goes.
Multiple members of SPECTRUM from red shirts to nearly-main characters are shot, crushed, drowned or pushed off cliffs. There's a fair number of scenes where the last you see of some red shirts is a flapping hand poking out from under a pile of snow or rocks that eventually goes still.
The crowning moment of this trope for Captain Scarlet has to be when the title character throws an electric cable into a Mysteron agent. He screams and catches fire as he's electrocuted.
The Dick Tracy comics had some horriffic deaths in them, and not only the villains either. One of the worst splatterfests was the story about Itchy. He shoots, stabs, and runs down cops, crooks, and uninvolved citizens with cheery abandon, and when Tracy finally catches up with him, Itchy decides to kill Tracy by somewhat graphically starving him to death. When Tracy finally shot him down like a dog, the readers were rejoicing.
Herbert Nirdlinger's murder in ACT Theatre's recent play of Double Indemnity was pretty traumatizing.
Thunderbirds has a number of harrowing deaths by implication: the first Fireflash to go missing was full of passengers. Seeing as the second one was intact on the floor of the ocean after crashing, one assumes all the passengers and crew of the first died of suffocation in the sunken aircraft while the aircraft's instruments were reading wildly off course.