"Previously on...": helpful every episode, or only season openers?
I initially voted all the time, because with programs bouncing around & other things in my life, I frequently miss an episode of something I really like. But it wastes a minute or two of what time is left after commercials, and there's almost always a way to catch up somehow online.
Personally, I HATE them any time
I hate them too. Unless too many people die or become zombies for me to remember. But most shows aren't too terribly complicated, and even if you miss an episode you can usually figure it out on your own in the first five minutes anyway.
Helpful when its bear grills. :)