Tina Fey has defined contemporary comedy for the last fifteen years, from her time as SNL's head writer and "Weekend Update" co-anchor on through Mean Girls, 30 Rock, and Bossypants. But what really matters is her hair. We kid! It doesn't matter at all — but it's interesting anyway, especially to those of us whose lives, intentionally or not, sometimes feel like they're one big exercise in Liz Lemon fan fiction. Side parts, center parts, soft layers, collar-grazing bobs: Let's journey back through Tina Fey's different looks over the years.