There's was a piece on NPR's All Things Considered in which a writer was telling about a book he was ashamed to love (Kurt Cobain's journals). It sounded like part of a series, but I haven't heard any others since.
Anyway, it got me thinking, and I couldn't think of a single book that I'm ashamed to love. The reason is simple, I think: if I love it, I really think it's good and am therefore not ashamed to love it. It doesn't matter who it was written for, written by, or how it was written. If I like it, it's good. If it's not good, I don't like it.
In other words, I define what's worthy by what I like, not by the expectations or opinions of other people. At least, that's how I am with books. Same goes for not liking something. I recently tried to read The Catcher in the Rye. I say 'tried' because I couldn't finish it. Aside from the incessant profanity and annoying way the narrator rambles on and repeats himself, I just couldn't get into the story. I'm sure some people can relate and a lot of people really like that book, but I couldn't stand it. Therefore, it's not that good, and I'm not ashamed to say so.
Music, on the other hand—I'm ashamed of about half of what's in my iTunes library. So don't ask.