Anything but Shivans works, but I voted for the NTF anyway. It would probably be the easiest to do, because they're still humans so you can understand their way of doing things.
A Vasudan campaign would only be good if there was actually a perceptable difference in the kind of missions, objectives of missions, etc. you get because you are Vasudan. Just flying Vasudan ships is not enough.
A Shivan campaign would be bad, period, because the Shivans are always greater in number, more powerful, etc. If you were a Shivan, there would be no overwhelming odds stacked up against you. It would either be a cakewalk or have a cheesy (and annoying) excuse for making the Shivans weak. Not only that, there is a reasonable chance the Shivans are some sort of robot or hive mind, but without knowing, you can't pull it off effectively. Even if you did know the way their mind works, it would still be very hard to represent that.