Considering shelf life, why do franchises like Godzilla to Predator hold up?

A lot of it has to do with timing - the obsession with sexual disease in the 1970s with Alien - the rise of testosterone heaving action stars/pictures for Predator - the nuclear-phobia with Godzilla. Some things just strike such a chord with cultures at the time that their impact is everlasting.

Now obviously a lot of these messages have been lost on many later audiences. Each of these franchises have either struggled to stay relevant with current events or have become watered down. Either way I'd say it's the initial reaction to their relevance that skyrocketed their popularity.

That’s a great question. I think it’s a combination of factors as well. It can come down to timing, story, characters, and even more importantly, the actors playing those characters, and the main antagonist creature and how it’s portrayed/conceptualized.

In the case of Alien, first and foremost you have a great movie/story. The characters are great and you really like and care for them. As for the alien itself, nothing like it had ever been seen before. It was and is an incredibly unique design and it was scary as all hell. The combination of those factors make that one special movie.

With Predator, first and foremost, you have Arnold. He was a huge box office draw during that time. His name alone was going to guarantee butts in the seats. Then you had a charismatic cast of testosterone charged characters who each brought something different to this ensemble. They were the Expendables before the Expendables! Now, you put this super team up against a very original and superior alien enemy, throw in some humor and awesome actions sequences, and you have the start of a franchise.

With Godzilla, although he’s been many things to many fans over the years, he too has always been a very original and unique creation. I compare Godzilla to the starship Enterprise from Star Trek (specifically the original). Each was an amalgamation of different things (Godzilla – dinosaur, dragon, sea serpent. Enterprise – flying saucer, rocket, airplane/jet) that came together to form something that was greater than the sum of its parts; again, something not seen before. Godzilla’s never been cookie cutter, from his unique roar, to the shape of his spines, and the fact that he not only breathes fire, but concentrated radiation! The first Godzilla is a cautionary tale, and something obviously that resonates with the Japanese in a vastly different way than the rest of the world. That first movie is so subdued and in stark contrast with most that came after it; for me it’s a very special movie and my favorite.

With these characters, there have been sequels of varying quality and in most cases, diminished returns, but they have had staying power and popularity I think because of their uniqueness. Long live the B monster movie!

Deep bra. I think more simply it is the mark they leave on society and the lessons they teach . These movies were so well done that people just can't get enough of it , and they keep trying to portray these characters better. They are so different than anything we had seen before , that we are never to forget them.

Movies like Godzilla have lasted so long because they are social commentary. The original was a response to the bombs. 1984 had the cold war. Shin had Fukushima and the current culture of bureaucracy. As with all good Science Fiction, as long as it is a medium to look at ourselves from a different angle it will continue to survive.