This morning I saw Flannel Pajamas, perhaps the best relationship movie I've ever seen.
It shows two people fall in love and then follows their painful process of realizing that they're not meant to be with one another despite that love.
Nicole (Julianne Nicholson) and Stuart (Justin Kirk) have a love-at-first-sight blind date after being set up by their mutual therapist and the sparks fly. The audience is told immediately that they will have problems based on the fact Stuart tells Nicole on this first night that her best friend is evil—he's made an instant judgement on her character after spending only a few minutes with her.
Despite this, the spark develops into an infatuation, which leads to good sex and a playful, nurturing relationship. Stuart wants to take care of Nicole; Nicole desperately needs someone to take care of her.
They are different religions (Jewish and Catholic), come from different types of dysfunctional families (his cold and distant; hers close and abusive) and don't seem to have a lot in common other than liking to sleep with each other. So they get married.
Like so many couples, they think the talks that they've had about major life decisions (pets, children, place to live, career) are somehow more negotiable once the rings are on the fingers and forget that marriage is techncially a contract, no matter how much you care for the other person.
Just like real life, their relationship gets worse and worse the longer they stay together. Each person's needs are ignored by the other and an overwhelming resentment sets in for the other person. They confide in everyone but each other and what respect they once had for their partner all but disappears into the despair.
Stuart has a didn't-know-how-good-he-had-it-until-it-was-gone revelation; Nicole realized he was never going to be the man she wanted him to be.
This film should be required viewing for every couple that gets engaged. It's cliché to say it, but it's true—sometimes love just isn't enough.