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FEAR AI is excellent: https://alumni.media.mit.edu/~jorkin/goap.html

The original Halo is similar. Play it on a higher difficulty level and the behaviours of the different enemy types are super immersive and challenging. It's available on PC as well. I haven't played the other titles in the series so I don't know if they kept the great AI.

While I love FEAR AI it was very much specialized for interiors. It wouldn't work in open world.

Old school good open world AIs think of Far Cry and STALKER. Especially the STALKER AI is pretty much one of the main reasons I keep replaying that game, all the unexpected stuff happening.

FEAR for FPS AI, and IMHO, Ultima VII for open-world NPC AI.