To get this out of the way: I create a supervirus with a huge incubation time and infect the whole world with it. Then I hold the world ransom for infinite money, promising to deliver the antidote.
I start with Madagascar, because fuck Madagascar.
When the secret agents inevitably turn up to steal the formula, I reveal I don't have an antidote and everyone is going to die.
Then I have the mind-controlled sniper rifle I hid in the wall kill them.
As I stand over their dead bodies, I get sunglasses out of my pocket and say to the world in general:
"Guess they were the only ones
...
to get their shots".