Ghidora curb-stomps. The Payday Crew and the GTA 5 protagonists with Lester vs. The Krusty Krab and the Secret Formula.
Krusty Krab Krew; how many times have you seen Spongebob and co. die? Arnold Schwarzenegger vs Sylvester Stallone in a pottery-making clash.
It would be close fought, but ultimately Saruman would be victorious. Dethklok can't do Christmas jingles like he can. Seth Rogen vs Jack Black in a triathlon?
Are you kidding? Spetsnaz. Even their entrenchment tools are designed to kill people. The Rock vs an actual rock?