The best and worst of Britney Spears' hair (in honor of her upcoming birthday, CD, documentary, comeback, etc, etc)

Britney Spears turns 27 next week and, to celebrate, we've created a retrospective of her best and worst hairstyles of all time (or at least, for the past 10 or so years). Starting with a cool photo from the latest Rolling Stone where BS looks gorgeous-sexy, but still vulnerable, healthy, pretty and strong (check out all of the pics here)-we've moved into some of the singer's less glamorous, more questionable follicular decisions. You know, the years of icky top knots, gross extensions, and oh, that day she shaved her head. Truth is, we love Britney and, looking through these pictures, we realized we feel like we know her. And, well, like any good friend, we're beyond happy that she's in a good place now, but need to poke fun of the bad times too. Just a little.