All the solo-MMO moments: exploring large maps, doing a lot of often tangentially related sidequest, coming back to old maps to explore previously unreachable nooks.
What? I'm a sucker for this genre.
Apart from that: the fights against dragons; the too rare moments when Banter was frequent; the bal at Halamshiral (hope the next game will have more cloak and dagger segments), the battle at Adamant Fortress, the Wicked Grace segment, the perverse satisfaction of knowing that a dysfunctional couple is the only thing stopping Orlais from collapsing.