A film let down only by its generic character relationships. Absolutely cracking script, full of biting wit and satire. Here are the Fantastic and compelling opening credits. The other links I've provided offer a lot of insight into the characters.
Yuri Orlov (Nicholas Cage) The typical ESTP. Great salesperson, very charming and witty, very restless; wants to do more with his life than sitting around doing nothing in a cafe. He continues to work despite his wife and kid leaving him, his family disowning him, and his brother dying as a result of his work.
Vitali Orlov (Jared Leto) More difficult to type. Most likely an ESFP. He's far more live-and-let-live than is Yuri, caring more about his hedonistic lifestyle than selling guns. His compassion comes through in the scene where Yuri is about to sell two trucks of weapons to the RUF in Sierra Leone, and he refuses to go through with the deal on the basis that as soon as they hand over the weapons, the entire refugee camp in the valley below is going to be massacred. He witnesses a brutal attack here and reacts poorly to it. (Interplay between he and his brother)
Ava Fontaine (Bridget Moynahan) Again, more difficult to type. This could be due to less screen time. Perhaps ESFJ, but I can't tell for certain. She seems predisposed with raising a family (yeah, yeah, we've seen it all before in countless other films), while her husband couldn't give two shits, shutting her up with a nice big diamond paid in blood. Only later does she come to realise the inhumaneness of his line of work, and refuses to cooperate with him until he stops. Eventually, she leaves him.
Jack Valentine (Ethan Hawke) Most likely an ESTJ. Highly concerned about the ethics of his work, and refuses to break any rules in order to capture the perpertrator. A typical One in the Enneagram, restraining his anger but letting flashes of fury through. Very admirable character. (His interrogation of Yuri near the end of the film)
Simeon Weisz (Ian Holm) May well be an INTJ. High class; mingles with the right people. He looks down upon Yuri, and tries to kill him when he becomes a serious competitor. Evidently a hardworking individual if he got to that level, but also a ruthless and scheming strategist. See him in action here.
Andre Baptiste Sr. (Eamonn Walker) An ENTJ in my opinion. Deliberate thinker, enjoys his power and position. Fundamentally good relationship with Yuri; they understand one another. Disconcerned with formalities, as illustrated here.
Andre Baptiste Jr. (Sammi Rotibi) ESTP is most likely. He's like a younger, more impulsive version of his father, who enjoys his hedonistic pursuits, with regard to none but himself.