The Oxford Book of Modern Science Writing by Richard Dawkins will become a treasure of the scientific community. Dawkins gathers 83 choice writing excerpts from the "Greats" of scientific writing (e.g. Pinker, Diamond, Turing, Einstein, Sagan, Penrose, Greene, Hawking, Chandrasekhar, Sacks, Oppenheimer, Wilson, Carson, Dyson, Snow... the whole list is here). The excerpts are each short (a few pages) but masterfully chosen, and Dawkins provides a brief discussion of each writer and their style before presenting the text. The selected excerpts discuss many of the central philosophical questions/insights of science, as well as many of its key contributions -- so readers are educated about actual science in addition to seeing how to write about it beautifully.
The book is thick, and I haven't finished it myself, but I can't recommend it enough for anyone who considers themselves a scientist. If science were art, this text would be like a distillation of the best masterworks from the world's best museums into a potent liquor that makes you feel guilty when you read from it because it is so rich and amazing -- representing much of humanity's collective accomplishments -- and undeservingly, you're still just sitting on your couch.
If you're looking for a holiday gift for a scientist, I would recommend this. Or if you're a scientist whose annoyed that your loved ones didn't buy you this book for the holidays, you can read a lot of it for free on google here.
An aside: If I ever get the chance, I hope to lead a seminar/clinic for phd students on scientific communication. I think this book on writing will round out the curriculum alongside Tufte's book on data display and Baron's book on communicating verbally.