kelseyr713: I think gaming depends less on gender and more on if you were brought up with it. My sister and I are both gamers and have been since a young age. Like others have said, the gaming tastes of girls are just as diverse as the gaming tastes of guys. It might be hard to find a girl you don't have to "convert," but we are out there.
To the OP, showing her the trailers is a great idea, and I hope you let us know what she picks to try out!
Zolgar: Pardon me for a moment whilst I pose a very .. atypical response:
If your girlfriend doesn't like video games, don't try to 'convert' her.
Have a meaningful conversation with her about her feelings of video games, as opposed to your own. Explain to her that while she may feel that they are a 'waste of time', entertainment is never a 'waste of time' (unless you're doing it instead of something you should be, then it's all miss-spent time).
Pose to her that the video game industry is just like the movie or book industries, there are strong games with solid plots and characters you can fall in love with.. and there are games that are mindless fluff.
Also, learn what her tastes actually are. You need to learn what she likes to watch and read, knowing your girlfriends actual interests (beyond 'normal chickflicks') is a very important thing in a relationship. Doing this will also help you to find the perfect game for her if she ever expresses an interest in playing games.
If she continues to dislike gaming, that is fine. In so long as she understands that YOU like gaming, and that it's the way you enjoy passing time. Do not let her try and change you, but offer her the same respect, do not try to change her!
Should you choose to ignore this advice, pay heed to this instead:
Do not fall prey to the "It has a female lead, it must be good for girls." - Tomb Raider was more geared towards men, as are many similar games. Actiony games with strong female leads usually feature scantly clad 'perfect bodied' women, that you spend an exceptional amount of time staring at their ass.
As well, do not fall prey to the "A lot of girls like this game." - The Sims for example, is not one that your girlfriend (as you have described) would enjoy at all. It holds no plot, has no measurable character development.. nothing. It's very hard for a person to grow attached and interested.
Learn her likes and dislikes. Truly learn them, not just a general ballpark.. does she read fantasy novels? Sci Fi? What authors does she like? Does she read romance novels? If so, are they sterilized, suggestive or, just-this-side-of-porn? Does she read erotica? In her romances and/or eroticas (if she reads either), what things does she like and dislike? What are her favorite movies? - You should be able to answer many of these questions, because.. you will be tested, oh yes. >.> Not saying you need to answer them here (though they might help people identify that 'one perfect game' for her.)
I will. Although she isn't my 'girlfriend'. But who knows :D
I already told her that many games have great back stories and let you feel a great experience while you are playing it. It is just like an interactive film or novel where you control the main character.