The final scene of this last episode (11) is one of the best TV moments I ever had the pleasure to watch. Walter's Joker laugh + Skyler's horror + Marie's crying + that sinister music in the background gave me the biggest chills ever, even when watching it a 3rd or 4th time. Absolutely brilliant!
The ending also created a huge number of branches for the action to take... can't wait to see which one is chosen. One thing is clear though... if Walter wants to survive and save his family, Heisenberg has to come out.