About motherhood: seeing little you's running around and knowing that you have a golden opportunity to teach them, mold them and give them the best you that you have to give.
About marriage: knowing that no matter happens in the outside world, that you are connected with someone who will always be there with you, even when things get rough.
My answers might sound corny to people. But it's how I see relationships in general. Simple and deep - without all the complications of $$$, petty behavior, and what-ifs.