Frankenstein meets the Wolfman (1943) was the *original* monster crossover, and something Universal hoped to build towards in their, now defunct *Dark Universe*
Other large Franchise crossovers people have wanted, that we got were:
Freddy vs Jason: Was financially successful, even if a critical failure. It probably should have happened about a decade earlier.
Alien vs. Predator Pretty much the same. Both films (even the sequel) did well financially, it was just their overall negative reaction by fans & critics that prevented further sequels. Again IMHO this also occurred about a decade too late.
Robocop vs Terminator, never made the leap form comics to film. At this point, I'm sure fans of BOTH franchises probably feel that was for the best.
King Kong vs Godzilla or/ Godzilla vs Kong This to me is different. Both characters have come in and out of the public's awareness many times over the decades. (Not just a product of the 80's/90's and got films too late) Also, unlike all those other franchises, this one is getting a far larger budget. I know we as Kaiju fans have been awaiting this for a long time, and up until...2016 or so...(Whenever LP/WB made the deal with Universal to get the rights to Kong), we never thought would happen again.
I'm going to enjoy it for all it's worth. Personally I thought KotM was a great film, and thought would have much more mass audience appeal, but I was wrong. I have little reason to believe General Audience reaction will be much different next year, but I hope I'm wrong.
Although it's nice to know fictional characters like this are seemingly timeless. Also I now we cant compare real life people to fictional characters, but I remember in the 80's when Hulk Hogan was dominating the WWF, and Ric Flair was dominating the NWA. Playground fantasy discussions about these two clashing were epic. Too bad when it finally happened in the late 90's, it was again, a case of a decade too late.
There are no more good TV Shows, only ones that haven't disappointed me yet.