Here's the things I never want to see in science fiction again:
1. Male pregnancy OR ridiculous alien pregnancy of a human like on Torchwood.
2. The Rapid Aging disease.
And the worst one that I just throw stuff at the screen for..
3. Alien something or other is Jack the Ripper. That a was a great story in Wolf in the Fold NO NEED to ever do it again. Sanctuary made a main character be Jack the Ripper! And the Babylon 5 ep was so deeply embarrassing it hurts to remember it.