This is, at best, a long shot, but it's perhaps the fashionista jaw-dropper. The runway shows of New York Fashion Week are a dream come true.
Typically, you'll only be able to get tickets to the upper level, not the floor (those seats are for industry insiders), and even then, the options are limited: For 2010 Fashion Week, AMEX cardholder status was practically the only way in.
There are also contests to win tickets offered by various fashion magazines and woman-related brands. Do a search for "Win tickets to 2011 Fashion Week."
If you can score your lady a ticket to a single Bryant Park show, you could probably play golf with your buddies every weekend for the rest of your life -- if that's your thing.
Either way, you'll have a very happy fashionista on your hands.