17. Jared Leto as Vitaly Orlov, Lord of War (2005)
If you're in the gunrunning business, you're inevitably going to arm some bad people who will use your weapons to commit atrocities. It's an unpleasant part of a job that makes money hand over fist. For some reason, Vitaly never considers this when he partners in the business with his older brother Yuri (Nicolas Cage).
After initially embracing the arms trade, lil bro starts to feel conflicted and becomes a full-blown drug addict, and later destroys half a shipment of weapons, fucking up a transaction with an African dictator who plans to massacre villagers. In addition to losing half the diamond payment, Vitaly dies for growing a conscience and nearly takes his brother with him before the civilians are slaughtered anyway.