Have you gone to a store with her in the past year where she mentioned liking something she saw? I loved it when my former love interests would listen to something I said in passing months before my birthday and then I would get it later as gift. It showed they cared and were listening. I know that seems elementary- but making a mental note of what someone said and following up on it is pretty cool. ;)
Barring that, the gift I'd most want to get is a romantic weekend away, so my suggestion would to be look up local bed and breakfasts or a trendy hotel based on what kind of gal she is. ;)
You just gave me a great idea, and, yes, I think she would like that. The trendy hotel, that is. Thanks.