Now that's a toughie.
I'm a big fan of movies and with a movie you never have to watch a DUNDUNDUUUUUUUUN filler (I've only ever seen one filler in any anime series that worked and that was Outlaw Stars obligatory hot springs ep).
But that having been said I still get the same excitment watching series and having to wait for the next one. I have very fond memories of DBZ when it aired on cartoon network. It was my one reason to stay indoors until after half four once I finished school :D.
So to answer I gotta go ith Series, since I still get that excitement. Besides movies never flesh out the story and characters as much they could (there are of course exceptions).
Now for my question:
Being forced to fight til you were dead (knowing you were unable to win) or being forced to kill another person who was utterly defenceless (knowing it would be your only means of surviving)?