Here's my opinion on T3 and this TV series:
Terminator 3: Rise of the Machines was well-made, well-executed, and even well-acted. It was a very entertaining and enjoyable film.... but I hate what it did with the story.
Sarah having died and Judgement Day happening anyway would completely ruin the series. The whole point of T2 was the epic, years-long struggle Sarah made to prevent Judgement Day and the war from ever happening, and when they prevented it at the end, it was the perfect endgame for the saga.
Whenever I watch Terminator 2, I always use the Easter Egg to enable the Extended Special Edition, which ends with the peaceful future scene with John as a Senator and Sarah the grandmother of his daughter. That's the REAL place their story went, in my opinion.
I consider T3 a completely non-canon alternate storyline. Fun, enjoyable, very entertaining, but not the real story at all.
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Now, as for
The Sarah Connor Chronicles, I just watched
the trailer for the series and I've got to say, it actually looks like it could be pretty good. I'll definitely give it a chance. I think the fact that they've set it "between the events of T2 and T3" is a problem, because it gives the series only one place to go. I think this should be a separate branch-off of the movie series, which gives it the oppourtunity to go in more new directions and tell better stories.
At any rate, I'm still game for watching, at the very least, the pilot episode to see how things start out, if nothing else just because I'm such a gigantic fan of the Terminator series.