The most successful celebrity marriages are definitely the quietest ones. The ones you hear the most about are usually because of problems or something crazy going on. If a marriage is good, you probably won't hear anything about it. The quietest celebrity marriages are probably the most successful due to this.
This is literally what I was thinking just a couple of hours ago. I'd never even heard of Alan Rickman's wife before yesterday - but they've been happily married for years, without a peek in these awful celebrity magazines. Rickman's career was built on being a terrific actor, and his personal life is exactly that: personal. When press and magazines and tabloids get involved, rumours spread, innocent pictures are blown out of proportion... no wonder these celebrity marriages never work, it's hardly a private life, is it?
The marriage between Will Smith and Jada Pinkett Smith is a great example. They mind their own business and just focus on their family. By steering clear of Hollywood drama, they have managed to survive as a couple and thrive as parents. Their children have benefited from the stability and low drama of their parents' marriage.
The quiet, prolonged courtship of this couple is refreshing, earnest and, ultimately, inspiring. So many Hollywood unions try to work on many levels: a union, a brand and a public relations/promotional vehicle. This creates a tight tension on the participants and pulls the intimacy away from the union. A quiet, deeply personal connection should be desired the most.