I'd argue the first and last are both unreasonable and unscientific, but the Agnostic Theist is still slightly less reasonable because he or she chooses to believe in something for which there's no tangible evidence.
I'd suggest there is nothing any more unscientific and unreasonable in being certain there is no deity running the world than there is in being certain there is no Isis, Easter Bunny, Dagoth, Sauron, Wizard of Oz, Loki, Cerberus, Santa Claus, leprechauns, Krishna, satyrs, Golem, Aslan, werewolves, Zeus, etc., etc., etc...
I think it is much more unreasonable to demand that a person consider the possible existence of all fictional characters or be labeled unscientific. Because there is certainly no reason to suggest that while we can be certain of the non-existence of all other gods and mythical beings, we must consider the possibility of the existence of the Judeo-Christian one or be called unreasonable. What makes him special when there has never been any more evidence for his existence than there is for the tooth fairy?
What is unscientific is to deny evidence that shows a supposition to be false. If the Judeo-Christian god came down here to my house and smote me with something improbable for my region, like a plague of Egyptian locusts, or filled my little creek with blood and made it run uphill, I would probably consider the possibility of his existence, but I'd still be more likely to try to discover the scientific explanation first.
There is no evidence to suggest the existence of a deity running reality, therefore it is not unscientific to be certain there isn't one. Certainty and rigidity are two separate things, and the application of scientific methods of investigation does not demand that we consider every potential possibility, just the ones we have evidence for.