Because you like Sam Fisher in Tom Clancy's Splinter Cell
Big Boss is a disillusioned mercenary commander who wants to create a world for soldiers (and soldiers alone). See them in Metal Gear Series.
M. Bison is a diabolical megalomaniac hell-bent on dominating the world. See them in Street Fighter.
A genetic experiment engineered to be the perfect assassin, Agent 47 is cold, professional, and lethal. See them in Hitman.
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.
After being resurrected and discovering his new morphing abilities, Alex Mercer uses them to combat the virus now ravaging New York. See them in Prototype Series.
Don't let his old age fool you, Heihachi Mishima is a ruthless pragmatist who values self-reliance above all else. See them in Tekken .
An assassin with supernatural gifts, Corvo Attano is the last guy you should frame for murder. See them in Dishonored.
For Kazuya Mishima, the power of the Devil is now his and his alone. See them in Tekken .
Liu Kang spends his days training his body and spirit, seeking to become the ultimate warrior. See them in Mortal Kombat.
If anyone can stay optimistic and friendly under harsh alien rule, it's Alyx Vance. See them in Half-Life 2.