Oh, how I wish this were a multiple choice question. Those that did not make the list but deserve to get smacked (the leaders, that is):
North Korea (self explanatory)
Sudan (even with "peace" they're still routing that southwestern area)
Belarus (Lukashenko thinks himself the second incarnation of Stalin, and it's straining Eastern Europe. Not to mention it being essentially a Stalinist extension of Russia the way he buddies up with Putin.)
Zimbabwe (damn parasite in southern Africa)
I don't like Musharraf either, but he is better than fundies getting the bomb.
My choice is for Saudi Arabia, if we were able to eat up however long the oil supplies would be cut (if everyone was involved, it wouldnt be long). Why? The major hotbed of terror. And even with the new King Abdullah enthroned in Riyadh being moderate towards the United States and the West, there are plenty of elements in the expansive royal family that provide funding to the radical Wahhabis and other groups. Finally, 15 of the people that attacked the United States nearly four years ago were Saudi, it shows what kind of environment new potential recruits found themselves in.
From there, it would then be onto the radical elements that have been chomping at the bit to take down the royal family themselves. What we replace it with is uncertain, but both groups need to go.