I have a greeting that is specific to a cell but I also have unique greetings for other npc's in that same cell. How do I make sure they will say their unique greetings over the cell greeting. Is disposition a good option or is there a better way?

You should just need to make sure that their unique greeting is HIGHER than the cell-specific greeting in the dialogue list.

Thanks Melchior. I wondered about that but thanks for confirming it. And yes, it seems to have worked.

Exactly as Melchior said. When game is trying to determine which dialogue line for given topic should be displayed, it goes from top to bottom of the list and chooses first line whose conditions are met. It means that the more restrictive the conditions are, the higher they should be.

Happy to help, Ashstaar. Dialogue is so funky in Morrowind. I've never actually looked at how it's handled in Oblivion or Skyrim. It'd be interesting to compare how they've evolved since TES3.