Over the last couple of years, I've been reading about a dozen Marvel titles from 1961 forward (the number fluctuates a bit as titles cancel or launch). I'm in 1989 at this point, and it looks like this is when Marvel started using its various titles' Annual issues as the platform for continuity-wide events.
More recently, Marvel seems to have gone with an approach of launching short-term titles as the platform for events, that may or may not also reach into the on-going monthlies. (i.e. the recent Hydra event).
Which approach do you prefer?