My favorite quote is the one that was in our wedding ceremony. It means a lot to us and we fully believe in each sentence:
Take the time to be gentle; remembering that words harshly spoken trouble the spirit.
Take the time to talk to each other; the secret to all understanding is in open communication.
Don't be afraid to say what's on your mind, and listen wisely.
Take the time to remember that you chose one another to learn and to grow with; you each have something valuable to offer.
Be a good teacher and a good student.
Take the time to be alone so that you can gather your innermost thoughts and share them with each other when you're together.
Take the time to be thankful.
You have chosen your path together; take the time to make it the way you want it.
If change is needed, do it gracefully.
Take the time to be loving; it is the one thing everyone needs.
Always, in marriage, take the time to give each other more.