The Saboteur

You will unlock this naturally as you go to clear all of the various events. The types of events are as follows:

• Collect Postcards
• Successfully complete stunt jumps (you don't have to land in a certain spot like in GTA, just go off of it enough to trigger the camera change and you'll complete it)
• Climb Scenic Points (requires you to climb to the top of a high building, you'll see a telescope, this is what you must reach for this)
• Discover supply caches
• Destroy Occupation Towers
• Destroy Sniper Nests
• Destroy Searchlights
• Destroy Radars
• Destroy AA-Guns (recommend getting on an AA gun and using it to blow up other things to save time)
• Destroy Tanks
• Destroy Propaganda speakers
• Destroy V2-Rockets
• Destroy Grand Cannons
• Sabotage Radio Controls
• Destroy Radio Tower
• Destroy Dierker Statues
• Assassinate Generals