Hulk vs. Thor

Watching the Loki possessed Hulk, savagely beating the Warriors Three. Especially the particularly brutal beatings he gives Fandral and Hogun.
Loki's voice coming out of the Hulk.
Thor: Why have you come here?!
"Hulk": Why to kill you of course, dear stepbrother.
Thor: Loki?
Banner's death, fully unshackling the Hulk for a time.
This segment has one of the scariest interpretations of the Hulk you'll ever see. Showing that Amora was right, without Bruce to act as a guide and restraining component. The Hulk really is a nigh unstoppable engine of destruction.

Hulk vs. Wolverine

Jeez, Wolverine got his metallic claws, you know that?!

In Wolverine's flashbacks to the Weapon X program.
The girl and her father inside the car within the town the Hulk smashed through. Logan initially imagines the Hulk bearing down on the innocents as a shadowy, advancing doom.
- Later on, when he finds out this wasn't the case, the flashback changes to show the truth. Weapon X's squad destroying much of the town while attacking the Hulk. The jade giant notices the civilians and tries to save them, scooping them out of their car and trying to shield them with his body. Sadly, the girl's echoing screams imply they were still killed in the crossfire despite the Hulk's efforts to get them out of harm's way.
Lady Deathstrike getting aroused from impaling Wolverine's back with her claws.