Supernatural's eleventh season recently premiered, so I'm here to bring you facts from throughout the show! Let's jump right into it!
1. Dean Wanted To Be Sam
That's right! Originally, Jensen Ackles auditioned for the role of Sam Winchester! But when Jared Padalecki came in and auditioned for Sam a slight recasting came along. The producers called Jensen and asked if he'd rather put his charm to use as Dean. He then accepted. Jensen later stated that he was previously interested in that role, because Dean was funnier than Sam.
2. You Could Have Called Dean
In the first couple seasons, Dean's cell phone number is given, and for a small amount of time, the studio had it set up so that anyone who called the number would hear Jensen Ackles saying: "This is Dean Winchester. If this is an emergency, leave a message. If you are calling about 11-2-83, page me with your coordinates." Nowadays, the number leads to a fax machine, but where the fax machine is, nobody knows.
3. Baby Brother Always Comes First
Whenever the brothers are introduced by themselves or others, they are almost always referred to as Sam and Dean instead than the other way around. This is a reference to the fact that Jared Padalecki's name is being shown first in the opening credits. Only in the eighth episode of the first season, and in the premiere of the eleventh season do they refer themselves as Dean and Sam.
4. The Winchesters Are Whovians (Sorta)
In the twelfth episode of the second season, there is a magazine that Ron shows Sam and Dean, the picture on it is a humanoid metal robot (or "Mandroid" as Ron calls them), with a caption that says "Cyberman". Both the name "Cyberman" and the likeness of the robot are references to Doctor Who. This is because the Cybermen are some of the main antagonists in the show.
5. Angel's Throat Hurts Too
Castiel (Played by Misha Collins) was only supposed to make a couple of guest appearances in the fourth season, but due to the fact that fans loved him, he had become a regular on the show. Misha has joked that he probably wouldn't have used such a low, grisly voice for his role if he had known that he would become a such big part of the show because it hurts his throat.