Because you like SHODAN in System Shock
It's hard enough fighting a war. But it's worse for Commander Shepard, knowing no matter how hard you try, you can't save them all. See them in Mass Effect.
Those who stand against this singular super ninja are doomed to fail. See them in Ninja Gaiden.
Dr. Gordon Freeman is a brilliant physicist is a quiet hero. And given all the violent aliens, he better be. See them in Half-Life.
Most of the world has been wiped out from The Beast. And when The Beast comes, Cole MacGrath will be ready. See them in inFAMOUS.
Bad-ass Rayne has sworn her life to finding and destroying her vampire dad, Kagan, and killing as many other vampires as she can in the bargain. See them in BloodRayne .
The Kid doesn't talk. He just acts with determination. See them in Bastion.
A jaded skeptic who only wants to get paid, Garrett becomes involved in bigger struggles that force him to be less self-serving. See them in Thief.
Raiden is an efficient soldier haunted by his repressed past. See them in Metal Gear Series.
Big Boss is a disillusioned mercenary commander who wants to create a world for soldiers (and soldiers alone). See them in Metal Gear Series.
He's an everyday earthworm turned intergalactic hero. See them in Earthworm Jim.
Gruff and efficient, Sam Fisher protects a nation that can never admit he exists. See them in Tom Clancy's Splinter Cell.
Fighting for a future without fear? Yeah, Chris Redfield believes it is worth it. See them in Resident Evil Series.