2. The Dialogue System
Here's something Fallout 4 detractors really don't want to admit; the old text-scrolling list of dialogue options wasn't always perfect. Say you'd entered a new area and talked to an important figure, occasionally you'd get dialogue choices pertaining to things your character wouldn't actually have known yet. You'd be able to enquire into the power structures of places, discuss leaderships after only hanging around a few seconds, or bring up peoples' personal relationships by saying names of others others you'd never met. Bethesda have clearly noticed this, and have adopted a more Mass Effect-style four-way decision system that (in theory) will keep dialogue options more focussed on topics that make sense, all while having everything voiced by your character to bring it all to life.