I was browsing DriveThruRPG for random encounter ideas for Dungeon World (a narrative rule-light game where the players are involved in worldbuilding), and found Joran Heimering of Windmill Slam Games' Random Encounter Compilation. I particularly recommend it if your narrative games are high on improvisation, namely asking the players to flesh out the background "what and why" of a seed, rather than having you do the work.
The booklet is only six pages long, but each of the five terrain encounter charts, each on one page has 100 entries. Each entry is a brief but often intriguing description. The download is for the On the Shoulders of Heroes campaign setting, but can be used for any generic fantasy world.
Frex, from the Forest, Moors, and Bogs section:
- Entrance of strange flooded crypt
- Elf wizard with human apprentice
- Tipped over halfling cart in ditch
- A suspicious scarecrow by road side
- Carpenter shop owned by old elf
- A wounded unicorn