Just Cause 2 is by far the best free roaming game I have ever owned. The size of the map is unbelievable meaning the best mode of transport is either extraction or use of the aircraft.
The biggest downside to JC2 is the storyline, the faction missions seem repetitive and the main storyline is short. Also, when doing the main storyline, expect to need a few attempts at, even on the lower difficulties!
Away from the storyline, the game really makes up for it; the graphics are remarkable. the mountains on the game have fantastic texture and the sea is by far the best I have ever seen. The map is split into the snowy mountains, to the rainforests and deserts, all of which are fantastically presented. The full map is playable from the start. As previously said, the aircraft is the best mode of transport, and when flying, the controls feel real! The plane looking similar to the 737 is controlable, where the military jets are less stable (as they are in real life). When looking down when flying the map is awesome, and it feels like you are on a plane with the speed the ground moves.
The game involves destroying all government owned peoperty and collecting nearly 10,000 collectables to improve your equipment, vehicles and health so the chances of 100% completion are pretty small.