Maelstrom

Now its track the bastard who shot you in the head and left you in an unmarked grave, kill him or not, and learn you're now somehow part of a three way faction war.

You can pick a side, or steal all of the glory for yourself.

In the end? There's gonna be a lot of dead bodies, and no princess.

I feel like you just summed up the plot to a Deus Ex game.

Fallout: New Vegas, actually.