Just Cause is the ultimate stunt-man game. Any free-roam is great for any gamer. The game is a great starter.
The story is a classic rebellion story. You are a one man army, and you have a massive arsenal as you play the game. The physics are very real and life like, but you can get shot as many times as you want and all you need to pick up health. You have an extreme amount of health, your practically invincible.
Just Cause is just the beginning. Just Cause 2, I've heard, has improved so much from here.