Among these Sci-Fi elements, which one is your favorite?

Among these Sci-Fi elements, which one is your favorite? Or you have some other brilliant ideas?

1) Explore the universe in a spaceship.

2) Artificial Intelligence

3) Go back in time

4) Take a peek at the future

5) Meet aliens

6) Alien abduction

7) Immortal

8) Parallel Universe

9) Undiscovered brain potential 

10) Superhero

11) Others