The Game: Call of Duty 4 (360, PS3, PC)
The Level: One Shot, One Kill
The Brick Wall: Assassinating terrorist a-hole Zakhaev is the easy part of the mission. Next you must carry your wounded ally to the extraction point at the base of the iconic Chernobyl ferris wheel and hold off an unrelenting crush of enemy soldiers till the rescue chopper arrives. One shot, one kill indeed. Anything else simply won’t cut it.
Stuck-o-meter: Medium; it’s a tough battle, but at least you always know exactly what your objective is: survive! This video shows the second half of the mission on regular difficulty.

The Game: Ghost Recon: Advanced Warfighter
The Level: Mayday! Mayday!
The Brick Wall: A tough on-rails section with a helicopter minigun, followed by a brutal ascent through the castle’s outer defenses. The only way to get past these sharpshooting rebels is to die over and over till you locate their firing positions, then try to take them down before they see you.   
Stuck-o-meter: Medium; once you’ve memorized where the toughest shooters take cover, you still have to contend with guys hiding around blind corners.

The Game: King Kong (360)
The Level: Millipedes
The Brick Wall: You need fire to burn some bushes and acquire a door handle. The only way to get the fire is to backtrack all the way to the start of the area. If you stand in just the right spot, you can see a fire urn on a cliff face through a tiny crack in the rocks. Shoot it with the sniper rifle (you kept that, right?) and it’ll tumble down into a waiting urn where you can use it.
Stuck-o-meter: Medium; you know there has to be fire somewhere, its just hidden in a cheap-ass manner.