#2 Blood Diamond
The same year as The Departed, DiCaprio also starred in Blood Diamond. Here, he plays a Rhodesian gunrunner named Danny Archer. The film was about diamonds mined in war zones that are sold to profit warlords, corruption, and diamond companies - at the cost of both the miners and the people living in these areas. It's a message movie with a lot of action and a tremendous performance from DiCaprio - all the way down to his Rhodesian accent, which from most accounts was pretty accurate. The performance earned DiCaprio a Best Actor nomination at the 79th Academy Awards, but he ultimately lost out to Forest Whitaker in The Last King of Scotland.