I was not expecting that.
Granted, I'm not quite sure what I was expecting but, on the other hand, whatever it was I might have been expecting, that definitely wasn't it. I think the last time I had occasion to say this about a TV show would have to be in reference to The Chicken Scene -- if you've seen it, you know what I'm talking about -- in the final episode of M*A*S*H (1983).
Though, now that I think about it, there may have been one or two Hill Street Blues episodes that qualify as well.
The final scene from The Usual Suspects also makes the grade, but that's not a TV show.