I'm a guy, 29 years old, who has just read Anne of Green Gables for the first time (at the behest of my fiancee).
It is a wonderful book.
You do not have to be a young female to enjoy the adventures of one. Anne Shirley is a delight of a character. She's brave and intelligent and so very earnest. It is a treat to read about her coming to live at Green Gables and the relationships she develops there. There's real depth in some of the characters, especially Anne's guardian, Marilla, who remembers, if only faintly, what it was like to be young and passionate, and is drawn irresistably to that in Anne and rejuvenated by it.
This and Tom Sawyer are the two great works about childhood in my experience. Yes--children would love to read, or be read, either of them. However, adults can get much out of reading them, too, and things that will not be available to the younger set. These books are both about children from an adult's perspective (neither Twain nor Montgomery were 9) and so an adult's perspective can assist in a reading of them, too. And, finally, while I'm certain that women are able to relate to being a girl on a different level than men can, we're all able to relate to the main virtues of an Anne Shirley and the beauty of childhood that she embodies.
Unlike the title of the current Spotlight Review, this is not just for any girl, but for any*one* with a scope of imagination.