Do you still talk to them occasionally? If so, I would do some research and find an artist you really like. Then, talk about that artist to them. Maybe tell them how you really want to get a piece of his/her work, etc. Find an artist you can obsess about, maybe they'll get you a calender of that artist! I think people understand that tastes change. If you approach it like that, it might not be bad. Say something about how the artist they're giving you is good, but gosh, have you seen so and so's work?? It's AMAZING!!