Well, the James Bond and Star Trek movies were typically about two years apart and they’re wildly uneven in quality, so waiting between movies is no guarantee of anything.
Among recent blockbusters, Back to the Future may have been the first to follow the pattern of “make the first, see how successful it is, and hastily arrange parts two and three”. There is one annoying problem with this, though. I find important elements from the first movie often tend to get changed or forgotten in the sequels, if they prove inconvenient:
[ul][li]At the end of Back to the Future, Marty’s girlfriend Jennifer is taken along “back to the future” with Marty and Doc Brown, at Brown’s insistence. Within the first five minutes of the sequel, though, Brown zaps Jennifer with some kind of stungun and she is tucked away, not to “wake up” until the end of the third film.[/li][li]Villain resurrection is another nuisance. Smith’s reappearance in the Matrix sequels never made any sense to me, as did the resurrection of Robert Durant in the straight-to-video Darkman II: The Return of Durant. This strikes me as giving the audience familiar pablum instead of coming up with something original.[/li][/ul]
There really isn’t a big enough sample to make a determination.
Richard Lester’s The Three Musketeers and The Four Musketeers were both pretty good, and they were shot at the same time – but they were supposed to be one film.
The mammoth Russian production of War and Peace, running more than eight hours total, was released in four parts in 1966-1967. In 1969 it won the Academy Award for Best Foreign Film.