Couples who seem like they go well together

Have you experienced that couples who seem to work best just seem or look like they fit with each other? I have seen couples who have been together for more than a few years that don't seem like they go together at all or I just don't seem to make sense. They seem awkward together.

I have a Cancer and Virgo friend couple who when together you would never know they were dating they seem awkward or like some friends hanging out. In contrast my Aries coworker and his Aquarius girlfriend just seem to fit so well together. They make sense and look cute when we are out and about.

Anybody else experience this and if so did the couple who seemed to fit stay together?