Over the years over on IMDb this question often pops up. Now I am often surprised in the answers that come back. But this year surprised me in the replies. One mentioned that its down to Jared’s agent that he is billed first. As I didn’t realize that agents have that power to demand their artist gets his name up top first. Apparently there appears to be competition, and money at stake.
Now many in the past have said its alphabetical which its not. Jensen Ackles in surname comes first, whom incidentally is the elder brother of the show (as if we didn’t know this fact). So Jared Padalecki if by surname would naturally come in second position. Unless alphabetical by first name, Ja comes before Je. Sam is the younger brother which to many were surprised that he was top billing. As in many cases elder siblings often come first, as they simply are the eldest.
Now my theory is that when Eric penned the draft of the show Sam was his MAIN character, and the stories revolved around him. This is simply why to me that Jared is top billing? He is the one with the supernatural journey the one with the mysterious and demonic power, whom is human also the one with the dark side in his nature. I also remember from previous replies fans talking about Jared is the first seen in the very first clip coming out from the bathroom talking to Jess.
Whether this has anything to do with why fans are upset over the years that Jensen is side-lined remains a mystery. But I think in later years fans have come to expect that they are now both leads, and all is fair and square. It has never overly bothered me and I understand why Jared’s name appears first on the shows credits. I am not over certain if they are on the same pay grade now either, which also remains a mystery. Perhaps you have another reason why he has always been billed first. I would love to hear what you have to say.