I would also like to know how Andie MacDowell keeps getting cast in movies. Her level of beauty is, to me, not high enough to counteract the fact that she can't act her way out of a paperbag with the aid of a blowtorch and a machete. Having said that, I adore Four Weddings and A Funeral.
Loved both Sense and Sensibility and Much Ado About Nothing--the Emma Thompson versions (Keanu nothwithstanding). I always feel like she's me up there, which is probably the point of a chick flick.
When Harry Met Sally is pretty much the winner of the genre. Everything about that movie is done right. Funny, charming, quirky, and not too sappy.
Loved 10 Things I Hate About You. Taming of the Shrew set in high school, and somehow it worked.
Is Chocolat a chick flick? That movie rocked.
Now, Voyager is one of my favorite chick flicks of all time. Bette Davis starts out an overweight, unibrowed "spinster," then gets and X-treme makeover, and ends up in an ill-fated love affair with a handsome French stranger on a cruise.
Way overrated chick flicks: You've Got Mail, Sleepless in Seattle, Life is Beautiful, Sabrina (remake), Titanic (Kate Winslet always seems a good 10 years older than DiCaprio, to me. I don't buy them together.), Notting Hill.
Edit: I have to also agree with wolfy--Lost in Translation was phenomenal. I loved the almost-romance, and the complete feeling of being plopped down in surroundings that were so unfamiliar that the loneliness was palpable.