Pegasus. Her commander was also the more ruthless of the two, as were her pilots. The key here is likely who gets in the first shot. If you follow the dialogue, Cain was trying to get her main guns trained on Galatica. If you look at the way the ships were positioning, Galactica was trying to remain on a parallel course to keep Cain's main guns off of her. That would put Galatica in the primary position, since her main guns seem to run along her spine. So, whoever gets in the first good shot would be the one who wins. Therefore, the big question is: Who'd shoot first in this game of chicken?