What would you like to see in an NPC mod.

I would like to try to approach this from a bit of a different angle. I have seen many post about what is a “good” NPC or “bad” NPC mod. This approach makes me a bit uncomfortable for several reasons. For one thing it seems to often get boiled down to an intense discussion naming a few different mods that some people have really taken a dislike to. I have even seen people who like such mods being labeled as having “bad taste”. From that point on, I see few other opinions being expressed.

Without giving the name of specific mods, what I would really like to know is what people would like to see more of. If you could write a mod, what are some of the things you would include. Remembering of course, that all peoples opinions are valid.

Just a few examples:
More interactions with other party members.
More personal quests.
Having the NPC fit in nicely with the PC’s quest.
Humor.
More serious situations.
More romance.
Unique NPC equipment.
Unique classes.
Mature content.
PG content.
Or anything else that you have always wanted to see.