Starbuck, Adama, Roslin, Apollo...all easy guesses for the final Cylon. Except that I haven't read anything to contradict the article that said that nobody in the "Last Supper" painting was the final Cylon. I guess a child of Starbuck's, or a clone, would technically not be Starbuck and therefor a possibility.
The drawing that D'Anna drew of the final five looks to have 3 men and 2 women in it but it's vague. We already know three men and one woman so there's a possibility it'll be a woman. I could also see it being Lt. Dualla. Dualla...duality? Yeah, maybe too obvious.
E...