Destroy All Monsters (1968)

The ninth* Godzilla movie has eleven kaijū in all, gathered together and housed on an island named Monsterland (not to be confused with Monster Island). The world will be in trouble if the high tech (i.e. piss-poor) barriers ever break, so let’s hope that never happens, eh?
If that wasn't enough, there’s a second threat that may well have had a hand in orchestrating the first. It never rains but it pours.
It’s fun but some of the kaijū are wasted; they're relegated to a spectator role while the usual suspects screech and thump their way to the finale.

3 invasions out of 5

*Rodan’s fourth and Mothra’s fifth. I'm not going to mention all the others. I’d be here all day if I had to list their origins and appearances.