Morrowind is amazing! I never really got into any later Elder Scrolls games for some reason though.
As for the poll, I generally prefer 'casual games', as long as I have the opportunity to be creative or make up my own story lines. Story games have to be really engaging to keep my interest. Also, every single one of my favourite games are ones that you can keep playing indefinitely, even after beating the main story (if there is one)
....I thought that story-driven games were typically considered casual games. D:
I rank practically all JRPGs to be casual, and those are heavy on the story.
Shooters aren't typically considered casual, but they also rarely have any story depth beyond "This is why you're going from Point A to Point B." I mean, sure, some aren't. Spec Ops: The Line is story-driven yet it's still far from cas'.
And all those pretentious art games walking simulators to release lately are both super cas' and story-driven.
This is way too broad and confusing, so allow me to be even less specific: "I like most things that are not sports games, but my mood decides the genre."
And I know the OP is looking for linear vs. non-linear, but just saying that would have made more sense. In that, I prefer sandbox games with a decent enough story to keep me motivated, but not on a 'set' path, like the Fallouts. So I guess my choice is "neither?"