The Conan books by Robert E. Howard; I know they're not RPG books but hear me out.
Robert Howard can fit a huge Conan adventure into the smallest space possible. Opening one story is like looking in the Tardis - Conan will seduce a queen, she'll get kidnapped, he'll ride vast distances, fight barbarians, then fight wizards, save her, then fight more barbarians and it's all in under 300 pages. The man was a genius when it comes to pacing which is a hefty problem for me and a lot if DMs I know.