I introduced my girl friend to the first 4 Star Trek movies... I think she wants to kill me 
I think you should have stopped before IV

First three are great. Particularly, the first Star Trek movie is awesome. Even today, it's beautiful, and the Enterprise's ambient is so clean with those 70's lines...
In the other hand, it's a saga that makes me feel very, very sad. I always dreamed of space and adventure as a kid, thanks to Star Trek, and I also learn the importance or knowledge and curiosity with the series/films. It made me dream of a future where mankind would be living for creativity, exploration and science. But this future is unlikely, as capitalism finally triumphed over any other type of society.