Over A Torrent Sea comes to mind. I had people tell me they were offended by the cover or how it was inappropriate in certain places.
But any offense is largely the individual's own fault, surely?

The cover isn't screaming "Look! Breasts!" or drawing attention to them, it's simply a (in my opinion, very beautiful) picture of an alien being in her element, which just happens to include mammaries. If someone's first instinct is to zoom in on those mammaries and make a big deal out of them, that's their fault, surely, not the cover's?

I mean, when I first saw it I was too busy appreciating the art to even register at first that she was naked.
I mean, what did people say to you? "Look, I'm sorry, but I was peeking at your book's cover as you read and there's a green-blue
thing on it with four breasts. Kindly remove it from my life at once"?