1. A copy of "How to poo on a date"
2. A suitcase
It would probably be misinterpreted and it would put you in a complicated situation.
Or, if it is intentional be franc and put her stuff in it.
3. A original personalized gift
4. A collection of house cleaning products
Even if you think you've understood what was her real passion, not sure she will enjoy it....
6. 2 tickets for a football game
"Oh you don't like football ....? Fortunately, my best friend does... So don't worry it is not a wasted gift"
7. A scale
A good way to make her understand that you lied to her: yes she did gaine weight and no you don't think that it's cute.
Anyway, that is not a good idea!
8. A pig's head
Apart from the fact that the video of her face opening this gift will probably make thousands of views on Youtube, this is a not a recommended gift.
9. SAW movies, the entire saga
A movie, why not! But choose carefully what kind of movie. And, SAW is absolutely not a good idea. (Unless you are a psychopath couple)