It depends. I'm not married or in a relationship, but if we were close, and i knew that's what she liked, then I would consider buying her a sex toy. I'm not sure why that freaks so many people out; I want to help her be happy and satisfied and it's not like I'm asking to use it in front of me. However, some people are still uncomfortable with the idea.
If we were more distant, I would instead buy her something else, like massage candles or body wash.