Because you like JC Denton in Deus Ex Series
A believer in the pursuit of justice, Garrus Vakarian hates it when bad guys slip through the cracks of the bureaucratic justice system. See them in Mass Effect.
Fox McCloud leads a team of pilots through the Lylat System in search of the evil genius Andross, the villain that killed his father. See them in Star Fox.
Raiden is an efficient soldier haunted by his repressed past. See them in Metal Gear Series.
Stoic, cynical, and brilliant, Solid Snake was genetically engineered to be the perfect soldier. See them in Metal Gear Series.
Fighting for a future without fear? Yeah, Chris Redfield believes it is worth it. See them in Resident Evil Series.
Riggan Thomson is a washed-up movie star running from his inner demons. Alas those inner demons look just like the superhero he used to play. See them in Birdman.
Jail hasn't broken Andy Dufresne's spirit, but will his spirit help break him out of jail? See them in The Shawshank Redemption.
Liu Kang spends his days training his body and spirit, seeking to become the ultimate warrior. See them in Mortal Kombat.
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.
Stuck somewhere between life and death, Talion is motivated by one thing only: vengeance. See them in Middle-earth: Shadow of Mordor.