I've had some pretty good experiences in Star Wars: The Old Republic lately. I still play pretty lightly, usually only doing a single step of my class quest during a play session. Right now I am playing on my Jedi Knight, who is at level 18. The rest of the post contains some minor spoilers about an early Jedi Knight.
When doing PvE content, it is pretty easy to zone out when doing mundane things like returning to a quest giver. We've all done it way too much, and it is pretty standard stuff. While doing a class quest on my Jedi Knight, I was heading back to my ship to give the quest giver a call when something strange happened.
I was going down a corridor and saw a bunch of people ahead of me. I'm pretty sure they were not there before. Hey, is that a red lightsaber being help to someone's throat? Oh, that someone is my companion Kira.... this can't be good. Of course, threats followed and then I beat up some Sith.
It was completely unexpected that something would happen on the way back to the quest giver. It's those kind of moments which really make me enjoy SWTOR. Their instance technology, which I love, makes that sort of thing possible. It's nice to know questing does not have to be so cookie cutter.