Open world sandbox games are a dime a dozen now days, but few can match the enjoyment that Just Cause 2 provides. You'll spend hours having a great time messing around in the environment. There are plenty of weapons, plenty of vehicles, and plenty of situations to create chaos. The grappling hook is one of the best mechanics in an open world game in a long time.
Add in infinite parachutes and you'll spend a lot of time approaching various situations from multiple angles. Just Cause 2 is a summer blockbuster packed into a video game, and if you enjoy action games you'll want to check this one out.