A Progressive Match

As Kathryn and Madison both mentioned, Admiral and Mrs. Croft have a relationship defined entirely by equality.  Personally, I absolutely love the relationship between the Crofts.   Finally we have a peripheral married couple who don't squabble about money or children or propriety, and instead just love each other.  The fact that Mrs. Croft cannot bear to be separated from her husband to the point of following him to sea is admirable and very new in these novels.  So often do we see men leave while women are simply left at home to bide their time until they return.  It's refreshing to see a wife who insists on coming with her husband, and a husband who doesn't mind her coming along!  This is especially highlighted in contrast to Anne's sister Mary, who--despite having a nice husband--is often left alone while he hunts or dines with others while she "watches" the children.  In my mind, the things I remember most about Mary are her complaints that her husband isn't there or that she's been left out.  To see her relationship with her husband in comparison to the Crofts makes them look even more united.  My favorite illustration of the Croft relationship is the scene in which they both drive the carriage.  The narrator remarks,
"But by coolly giving the reins a better direction herself they happily passed the danger; and by once afterwards judiciously putting out her hand they neither fell into a rut, nor ran foul of a dung-cart; and Anne, with some amusement at their style of driving, which she imagined no bad representation of the general guidance of their affairs, found herself safely deposited by them at the Cottage."
Austen herself characterizes the Croft's marriage by this moment, in which they both work together to perform a common task and, without discord, achieve a common goal.  This kind of marriage is entirely new to Austen literature in my memory, and might serve as an example to women of what the new "ideal marriage" looks like.