In my opinion, Halo 2 had the best dialogue for any Halo game, scripted, or non-scripted. There are countless quotes from Truth, Cortana, Chief, Johnson, the Gravemind, and even your neighborhood marines.
Something I missed from Halo 2 was the their were random AI conversations, which were funny.
No, not like tank beats everything, which plays every time you play the Ark, I am talking about random, non scripted dialogue.
I cared about the AI in Halo 2 more than any other Halo game, because they were human.
For example, if an AI cracks a joke about how ugly the aliens are, the other guy would congratulate him.
“Hey, take off your mask, you can’t be that ugly?!”
“Yehahaha, good one amigo”
Or, when an Elite dies, there is a random chance of this happening.
Elite walks up to dead body
“He is no more”
or when you get a headshot
“Nice one”
“Hey, you might be as good as me one day!”
or when a marine chucks a grenade
“Hey, fella, catch!”
And this was random, non scripted dialogue.
In short, one of the best ways to make people care about AI is to make them more human. Random dialogue is a great way to do this.
Although other Halo games had this, I felt that the marines weren’t actually communicating with each other or me as much, but just shouting random retorts.