As a professional counselor, I can tell you that it's critical that couple's share very realistic expectations about what a long term relationship really is. Popular romantic comedies and sitcoms are not the place to learn about these more realistic expectations.
As far as contrasting perspectives go, on money, sex, in-laws and parenting (common sources of relationship distress leading to breakup and divorce):
I think maintaining a healthy, long term relationship is more based on learning and jointly implementing tested relationship-maintenance-skills (like communication problem solving; and basic needs meeting) then it on actual value contradictions.
In most cases, It's more about effectively managing and negotiating differences of perspective through communication and compromise then it is about the differences people have coming into the relationship or keeping it strong.