We need to change the way we see seasons of a TV series. Every season is an absolute definitive ending. It's just like a feature-film - there are absolutely no guarantees for a sequel. Every season is made with the knowledge that this one season ordered is as far as it goes. Even if more than one season is ordered, they have to make each season as a new ending because the following season could still not happen and is still yet unmade.

Even with something like the "Star Wars trilogies". It can end on any one of the installments and there are no guarantees to continue. Look at Carrie Fisher's death and how that ruined the plans they had for the next film. And even plans are just ideas that will change if and when they make another film.

SPOILERS FOR THE EMPIRE STRIKES BACK: The Empire Strikes Back is not a cliffhanger, it's an ending. The thematic point of the ending is the loss of innocence and naivety.

Luke's mentor and father-figures lied to him and kept the truth from him. The legendary figures he looked up to that he never met (his father) is not who he thought he was. Princess Leia is now with the scrappy side-character and not with the lead chosen one, a new secret boy toy she has. She may be keeping both Luke and Han on her lovers' list, like a real-life woman would do and not adhering to some fairytale 'it has to be this way where only the main hero and princess can be together with no infidelity'. This Yoda Luke was looking for isn't some badass elegant human in a palace that looks like him, but some little green booger that acts crazy and lives/hides in a swamp. Yoda is keeping another secret from Luke: Luke isn't the only chosen one and everything doesn't truly hinge on him ("There is another."), but he basically lies to Luke and tells him all will be lost if he doesn't do as he says. Luke could now die confronting Vader and it wouldn't really matter because it really doesn't hinge all on him, but Yoda needs him to believe the lie.

The point, the change, the ending is that life is not what we've been led to believe all our lives growing up. It's not simply good vs. evil, it's not black and white, it's grey. They may never get Han back. Luke now no longer wants to kill Vader, but wants to talk and understand him because he's unknowingly looked up to him his whole life. He loves him. It's his father.

It's one hell of a beautiful ending. Just because it leaves the viewer in absolute wonder and awe, doesn't make it any less of a definitive ending. Not every ending has to end with "the good guys" happy and "evil" defeated.

Sure, you can continue the story (and they did). Though, I was not a fan of the direction they took the next installment and I like whatever my own imagination conjures from the end of The Empire Strikes Back instead of what they made with Return Of The Jedi.

With a TV series like Terminator: The Sarah Connor Chronicles, despite the creator saying he has a 4-season plan, it's not really an unfinished story if only two seasons are made. It's a complete and whole story with the first season. The second season extends that story and makes it a new whole and complete story. (And you also have the three feature-films it's a sequel to).

They make the story up as they go along, one season at a time. The 4-season "plan" is just a very loose blueprint and direction to go. The creator has since revealed his plan and it's totally different from what they actually made. There are general similarities, but for the most part it's very different. The ending of the actual Season Two that we got was his "planned" Season Three ending. And that ending is basically the same as his "planned" Season Four ending (it would have been redundant). The ending of his "planned" first or second season was basically relegated to a mostly off-screen subplot of the actual Season Two.

Even with the first season that was supposed to be 13 episodes, but was cut off by the writers' strike after they wrote episode 9, they still had to set-up, film, and edit those episodes. They know what they're doing and that this is all they get to make and tell of a story. There's a theme (in the last episode of Season One) of enjoying the moment, life, because it can suddenly end at any moment for any of us. One character asks another how do they explain to a little boy that robots are taking over the earth. "You don't."
You can be enjoying a moment and then it's gone, cut off, ends suddenly. It really summed up a great message that it ended on. Don't take life for granted because it's going to end and you won't know when.

The second season is probably the best ending to any series I've seen. It is a complete whole story. It's not "cut off in the middle". Sure, the story can continue, like any other story ever made, but it is an ending, a definitive one, like any other.

I've come to realize that with time travel in the plot, the end of each season can be the beginning of the end of the next one. Still it was fun to watch while it lasted.

Thank you very much for your responses. I'll give it a shot! :) @Xyberfaust Especially for a VERY thorough answer, you didn't have to do that. :D