Biggest surprises or unexpected turn of events (SPOILERS obv!)
For me, the biggest one was in the end of Episode 1 - I literally said "wow" when watching it on laptop and had to explain it all to my wife - it was revealing that Chuck's mistress is none other than his wife.
Also that Bobby didn't cheat with blonde girl during Metallica gig - usually those kind of encounters in movies/series end only one way.
Mildly unexpected was Bobby's rescue of his sons from the camp.
There were others but I have to look them up again.
What were yours?