The Mars Trilogy - Kim Stanley Robinson

Some of the first sci-fi books that really hit me when they were first published. Kim Stanley Robinson's masterwork - three books that explore so many themes around deep science, politics, culture, and the clash of human civilizations. Exceedingly well researched with a lively cast of characters.

Red Mars, Green Mars, and Blue Mars form the core trilogy, and there are a handful of additional stories set in the same world if you (like me) want to go deep: The Martians.