The following is a guide to the conversations that can be held with NPCs in Diablo III. There are 14 conversation achievements in Diablo III, 1 of which is unlocked by collecting all of the achievements, and 3 of which unlock by collecting the remaining 10. If you always talk to everyone you can, as often as you can to see if they have new dialogue, then you will get all of these naturally, otherwise you can check here and the more detailed guides linked within to find every conversation you need.