This is actually a surprisingly complex question, because standards of beauty change dramatically even from one generation to the next. For instance, my mother who was born in 1947 (so the classic Baby Boomer) has remarked that when she was a teenager/young adult in 1960s America, the standard for a beautiful woman was one who had a small waist, shapely calves, large thighs (that is, no "thigh gap." The thighs were expected to touch when a woman stood with her feet together). Contrast that with today's standards, which are almost the exact opposite (though the small waist still seems to be desirable, provided it comes with defined musculature).

As for Anne Boleyn in particular, it was always noted that she was not considered conventionally beautiful for her era, but she had a magnetic personality that apparently made up for it. Also, it is thought that the intense attraction between her and Henry was partly to do with similar passions for music and dance. She was an accomplished musician and dancer, as was Henry. According to The Life and Death of Anne Boleyn by scholar Eric Ives, contemporary accounts relate that she was "reasonably good looking" with a swarthy complexion (not pale, as was the beauty standard at the time), had small moles on her face, was "of middling stature" (making her neither tall, nor short for that period), and had a "bosom not much raised" (meaning she was probably relatively small breasted in a period that preferred women to have a larger bosom).

For an idea of what a beautiful woman looked like in sixteenth century England and France, here's a couple of portraits:

Mary Tudor, sister to Henry VIII, dowager queen of France and Duchess of Suffolk

Diane de Poitiers, mistress to Henri II of France, who was in her fifties when this portrait was painted. Was widely regarded as one of the most beautiful women of the time. There are many paintings of Diane during during and after her lifetime, but I like this one because it gives a more faithful representation of her looks than others which veer towards idealizing her features.

Marguerite de Valois, daughter of Henry II and Catherine de Medici. Not only was she considered beautiful by the standards of the time, she was renown for her wit and intellect.

Mary, Queen of Scots was also hailed as a symbol of contemporary beauty, despite her height. She stood at around 6 feet tall, at a time when the average height for a woman was closer to 5'2".

Lettice Knollys was another woman whose appearance was described in favorable terms.

You get the idea. Comparing modern standards of beauty to historical standards is very much like comparing apples to oranges. It's impossible to know for certain if someone like, say, Kim Kardashian, who our modern society considers beautiful, would be considered beautiful if she were plopped down in the court of Henry VIII. And I can't put too much stress on the fact that more often than not, it wasn't so much a woman's physical attributes that determined her status as "beautiful" as things such as the way she carried herself, how graceful she was in attitude and comportment, how accomplished she was in music and dance, whether she was literate and could write, and how many foreign languages she was able to speak to the point where she could carry on a conversation with a native speaker. It was these factors that tended to override the physical attributes of an elite woman and made her "beautiful."

If you're interested in this sort of thing, I recommend you pick up Ladies-In-Waiting: The Women Who Served The Tudor Court for a good introduction to how women were viewed as courtiers and what phsyical and personality traits made them eligible for high status servants to the Queen.