Three pages of thread, and I've yet to see anything about what she happens to be interested in. Have you tried asking her if there is any interest in any type of game? What kind of things she likes? If you have, and report here...we could probably give more informative answers.
Personally, the gateway drug for my wife was Resistance. She likes games "with story", happened to be walking by when I was trying the demo, and wanted to try the co-op with me. Fast forward and now she's going out and buying shooter games before I do (not as cheap as me). She's also a lot more open to playing any type of game, where there was a lot of resistance before.
Lastly, (and no idea if this is a problem), but are you making an effort to try her hobbies too? Best case scenario you're both trying each other's hobbies together.
EDIT: +1 for pixel junk. I own a ton of AAA games, and when folks come over it always comes back to pixeljunk. Sony has made several PS3 sales due to this, lol. Plus it's easy to get into, and has that "fun/addictive" type gameplay. Just be sure not to be too bossy, haha. (which often means saying
anything)