
I would LOVE to see Anguirus, being Godzilla's sidekick (like he was in Gigan, or Mechagodzilla '74), but mainly I want to see Godzilla kicking Kong's butt. I wouldn't be opposed to a team-up movie having the real villain be Biollante, Destroyah, someone like that.

Red Berry Juice
Lightning
A minimum of 1 castle
Dancing natives
A satalite
People placing bets on the fight
Host of the podcast Giant Monster Messages where we watch EVERY giant monster film and look for the messages.

There's supposed to be some kind of Human conspiracy going on.
I'm thinking that perhaps Kong and Godzilla will be incited into conflict with one another through Human interference, perhaps an attempt by terrorists to both get rid of the Titans and harvest the aftermath for black market goods.

That sounds pretty good.
Host of the podcast Giant Monster Messages where we watch EVERY giant monster film and look for the messages.

EmptyH,
Your list is spot on.

Ideal Fantasy Scenario: Godzilla and Kong fight a bit then team up to the beat the crap out of Gamera. There are no human characters.
Best Realistic Scenario: Godzilla and Kong fight a bit then team up to fight Mecha-King Ghidorah. Human characters are mainly superfluous.