Tossing in my two cents.

I noticed no one said trust. Without trust, you really have nothing - my opinion. Trust that that person will uphold their vows (otherwise why make them?), be there for you (good times and bad), you can trust them with all of your secrets and dreams and know they are safe. Trust that they're going to uphold their end of the bargain...whatever the bargain may be. And that your partner knows they can trust you just the same. Trust is a powerful thing.

Also (and I think this is as important as trust) there's acceptance. We all come from different backgrounds (even if you grow up next door to your partner, you grew up a different way) and a big part of making any relationship work is accepting that this is who this person is and not try to change them to suit you and your views on life. Being accepted for who you are and being loved for who you are (warts and all) is one of the greatest gifts one human being can give to another. And when it's your life partner that does it...it just makes life that much sweet.