Nobody's been here for a few years, but still, I have to say my favorite mission is Night of the Jackal. Plenty of mission variety, some cool weapons, interesting locale, all make this a really cool mission. Second place would have to be Mediterranean Crisis, especially when you discover that your progress in the previous mission, Poseidon, directly influences how you start that next mission.
"You shall know the truth, and the truth shall make you mad." Aldous Huxley http://codereddnet.blogspot.com