I think Heroes is an example of this 'infinitely flexible format'. It really seems like anything could happen. Characters are introduced and then just kind of fade into the background - and continuity - well, sometimes it feels obvious that it's played with, quite a lot. The beginning and ending of episodes, for instance. How often do we see a scene from another angle and realise that it's slightly different - a line of dialogue here, a pause there? Not to mention, we also have the whole playing with the timeline aspect to deal with.
And I love Heroes. I look forward to it in glee. I watch it and clap and shout at the screen - it engages me a hell of a lot. Also, at the moment, I am absolutely adoring Doctor Who - and completely looking forward to both John Barrowman and John Simm appearing later in the series.
So - I think what I want from a narrative is changing, in some ways. I don't necessarily need a strict adherence to certain rules. But obviously, it depends on how well something's done. Heroes is mostly well acted, well shot, well edited, with interesting characters, good dialogue, and a decent sense of humour. Doctor Who is the same, and also ever so slightly more camp, which I love.
I'm sure I had a point here somewhere, but to be honest, I've kind of forgotten what it was. Er, yeah. (Yay, television?)