Marc, Star Trek does work, because they use the correct time travel theory.
There are a few, but the two main ones are (to avoid paradox):
1. What has happened will always happen. In Star Trek 4, the crew go back in time, but don't alter the time line in the future. Likewise, in "First Contact", the crew go back in time - but they ensure the time line isn't ruined. What happened always happened. In both cases, the time line is held solid.
2. When you travel in time, you create a split in the time lines - alternative dimensions. This is how the new Star Trek handled it. In this case, when Spock (and the Romulans) travelled in time - they did so to a new dimension, created because they caused an alteration in the time line. This rupture is created to stop paradox.
If in First Contact the Borg had stopped the launch of the warp drive ship, then the entire Star Trek universe would have collapsed. So, they either
had to fail, or if they had won, then a new alternative dimension would have formed around them - with a new future. This timeline would no longer be able to interact with the old time line. This is what we have with Star Trek now. Both timelines run parallel and separate and must be treated as two different entities.
Terminator shagged this by just making things up as they went along. Having the future affect the past, which affected the future and it all just collapsed in a black hole of paradox - because they never had a time travel back bone theory to base the story on (they're just action films and you're not meant to think too much about them as their plots are holey at best
).
Anyway, I thought Star Trek was okay. I'm in no hurry to watch it through again. It seemed a bit pushed at times to shoe horn in bits of story which needed to happen. The flow wasn't quite there. It also didn't happily straddle the line between Trek and action - it wasn't enough of either to be a really good film (not that Trek films are often any more than "alright" mind :lol: ).