Here are some of mine!
"Pick your battles."
"Would you rather be right or loved?"
"Nothing else matters but the family you have now. Your mother doesnt matter, your father doesn't matter, don't give anyone or anything a second thought but the family you're raising right now."
"Men are not attracted to women who wear ugly, stained, ripped-up underwear."
"Some days will be easy and you will love each other. Other days you have to work at it. You never see the hard days in a photo album... but those are the ones that get you from one happy snapshot to the next."
"It can't be 50/50, it needs to be 100/100"
"Never do anything for your husband that you don't intend on doing for the rest of your life. "
"Don't even THINK about marrying someone that can't say/do these two things-
"I'm sorry"
"I will try harder" -and then does "
"We are all allowed to have bad days just not on the same day!"
""Never treat your spouse worse than you'd treat a friend"

"Try to be a person that YOU would want to live with"
And my favorite from Captain Corelli's Mandolin:
"When you fall in love, it is a temporary madness. It erupts like an earthquake, and then it subsides. And when it subsides, you have to make a decision. You have to work out whether your roots are become so entwined together that it is inconceivable that you should ever part. Because this is what love is. Love is not breathlessness, it is not excitement, it is not the desire to mate every second of the day. It is not lying awake at night imagining that he is kissing every part of your body. No... don't blush. I am telling you some truths. For that is just being in love; which any of us can convince ourselves we are. Love itself is what is left over, when being in love has burned away. Doesn't sound very exciting, does it? But it is!"