Although I was young when I experienced this, to my mind there were three really insane, all-encompassing 'manias', where a movie was so popular that almost every store was selling endless merchendise, there were TV shows, mass-marketing, action figures were the must have toys.....unavoidable hype. It literally was everywhere, much more so than a huge movie of today, such as say Transformers or even Harry Potter. These days, there are so many huge movies they have to share the hype and attention. Back when these movies came out, it was one monolithic blockbuster that owned the summer.
These three were Batman in 1989, Jurassic Park in 1993 and Star Wars: Episode I in 1999. As I recall, The Phantom Menace was the most absurd and overwhelming. I remember walking around a shopping mall in England and almost every store had Star Wars stuff. It was absurd.