Supernatural stars Jensen Ackles and Jared Padalecki as Dean and Sam Winchester, two brothers who travel the country looking for their missing father and battling evil spirits (demons, vampires, amongst other things) along the way.
It is one the best TV show of all time. Every season is better then the previous one (there is 5 seasons of it now). Watch it now because it rocks, it kick is ass, and there is always something to look forward to in this show. It is on the CW on Thursdays, 9 PM. Though no other channels show it (re-runs that is, which is a disappointment)