[Lammy]

Ender's Game and especially Ender's Shadow. I hesitate to recommend OSC at all due to his Problematic™ personal politics, especially as a member of the maligned group, but they had a big impact on the way I see The System in which we all live.

Spoiler-free: based on a shared societal belief in a looming existential crisis, a group of young adults attend a military school whose curriculum revolves around a war game with sports-like rules. The System uses the war game to identify for positions of relative prestige those students most willing to interpret the game rules in creative ways, most willing to question assumptions brought with them from the school-world into the game-world, but naïve enough to believe the game is over once they've “graduated” from it. The books explore the many ways in which the “real world” : school-world :: school-world : game-world.

[tetris11]

Enders Shadow was the real series. I don't quite like how it ended, but that's OSC for you.

[ddanieltan]

I remember being very disappointed reading Speaker for the Dead, in that it's a total change of pace from the more "hero's journey" structure for Ender's Game, but now looking back, I really appreciate how it expanded the themes and brought a more nuanced flavour to the whole series.

And yes... I try to separate the art from the artist too when it comes to OSC.

[mooreds]

I think I recall reading that he wanted to write "Speaker For the Dead" first, but wrestled with it so much that he had to write the prequel.

Ender's Game is definitely a classic.

[jhbadger]

Although if you read the Frank Herbert's Dune books you see that Card was kind of doing the same thing with Ender as Herbert did with Paul. The first books of both series set up the protagonist as a hero, and the later books deal with the fact that "heroic acts" often have consequences.