The first couple Halo games had really impressive AI.

The last couple MGS games did as well, if I remember correctly.

Uncharted 4 had pretty decent AI on the harder difficulty settings. Trying to blow you away from cover and trying to flank you from multiple sides.

This here. F.E.A.R. has some really good flanking AI, and the AI doesn't seem too bad otherwise either. MGS is nothing spectacular but it just works really well in the games. Beyond these two, I don't think I really have anything to contribute to this thread.

Lol I know right. XD

This is a difficult question I’ve been thinking about it like all day now. People mention FEAR and Halo but I haven’t played those.

Halo Reach stands out for me; not only did different enemies have very different behaviours, but they were very reactive, constantly changing up their tactics in response to how the player behaved. They'd push forward when your shields were offline or if you retreated, flee or take cover when vulnerable, flank your position, etc.

I think the original Halo, Combat Evolved, was the first time I really felt impressed by in-game AI. I still think the enemy AI in that game holds up better than most games today.

Alien Isolation.

Even today, F.E.A.R. still comes to mind.

I mostly like the friendly AI in the Naughty Dogs games, not perfect but way more useful than most sidekicks.

The fear trilogy is pretty neat especially fear 1

The AI for Trico in the Last Guardian was amazing. From the way his animations adapt to the environment to all the little quirks that make him feel like a real animal. Yes, that includes the frustrating moments wherre he doesn't behave like you want him to. Like it or not, the developers have stated this is by design