I skew towards post-apocalyptic/apocalyptic in this category. I can't seem to think of space colonization without the idea that something that will go horribly, horribly wrong. I feel a bit of unholy glee when I read them. And on that note, I present my favorites.
Nightfall by Isaac Asimov with Robert Silverberg
What happens when you live on a planet that is constantly illuminated and you experience a solar eclipse that has never been recorded in your planet's history?
Off Armageddon Reef by David Weber (Safehold Series, book 1)
ARMAGEDDON. Heavy religious imagery, and cults, but it's all perpetuated by manipulative humans.
The Gods Themselves by Isaac Asimov
It's based on a line by German playwright Friedrich Schiller: "Against stupidity, the very gods themselves contend in vain." I bet you can see where this is going.
What are your favorites?
ETA: Kinja is being awful with images. I guess they're now disabled on the subblogs?
ETA2: Mebbe it's back?