And this is why TV Tropes is awesome...

[Uncle Nutsy]

[url]http://tvtropes.org/pmwiki/pmwiki.php/Main/HyperspaceIsAScaryPlace[/url]

How bad is the Warp? The Tau Earth Caste cheerfully use any and all technologies to help spread the Greater Good. After their experiments on Medusa V, they've basically decided "screw that, too many tentacles" and are sticking with their much-slower-but-won't-lead-to-daemons-raping-the-flat-bit-of-neck-where-your-head-used-to-be method, which just skims the edges of the Warp; it's rather like sticking to the coastline - you don't get very far out, but that also means you avoid the sharks. Except that in this case the sharks are the size of your ship, and are able to pass through the hull and eat the crew, and drive you mad to look at them.

[url]http://tvtropes.org/pmwiki/pmwiki.php/Main/FateWorseThanDeath[/url]

And the less said about those captured by the Dark Eldar, the better. One novel describes the victim of a Homunculus' attentions as a collection of skin and organs hanging individually from the ceiling on metal hooks... and the poor guy was still alive.

[url]http://tvtropes.org/pmwiki/pmwiki.php/Main/MindRape[/url]

The entire training of a normal psyker is like this too, as evidenced by the "sanctioning side effects" table in Dark Heresy. Among the results are: eyes burned out, white hair and gibbering, hair loss, chanting scripture in your sleep, visibly grimacing and twitching whenever you hear mention of Holy Terra, and believing that parts of your personality that were forcibly removed have gained sentience and are tracking you down.

[Commissar Lewis]

And I think a group of us Tropers on there made a custom Space Marine chapter.