Assassin’s Creed - Assassin’s Creed is a best long running and extremely popular series of open world video games which mixture of action, adventure and more importantly stealth into a single experience.
Sniper Elite V2 - Sniper Elite V2 is a Fantastic, Action-Adventure, Stealth, Co-op, WWII, First and Third-person Shooter, Tactical, Single and Multiplayer video game created and published by Rebellion.
Middle-earth: Shadow of Mordor - Middle-earth: Shadow of Mordor sets you in the middle of The Lord of the Rings galaxy when you combat orcs using unique wraith expertise.
S.T.A.L.K.E.R.: Shadow of Chernobyl - S.
The Saboteur - The Saboteur mixes in the regular setting that many open world action adventures travel to simply by using a World War II theme instead.
Arma II - Arma II is an Awesome, Action-Adventure, Military-themed, FPS (First-person Shooter), Tactical, Co-op, Strategy, Single and Multiplayer Simulation developed and published by Bohemia Interactive.