What kinds of things to men like to hear?

My boyfriend and I have been dating for a year and a half, and I know pretty much everything there is to know about this kid. We're both 16, and everyone says we're so much more mature beyond our years. We are not sexually intimate (and don't plan to be until we get married) and we treat each other with the utmost respect. I just want to know some things I can say to him that will make his day and let him know that I really care. :)