There are so many things in life that make me happy, so choosing what makes me happiest is difficult to nearly impossible. While dressing does make me happy, very happy, it is not near the top of my list.
Like the OP, my wife probably is what makes me happiest, because nearly everything else that makes me happy, including dressing en femme, is better when I do it with her. I love all types of outdoor activities and am very happy, cycling, hiking, climbing, SCUBA diving, to name just a few activities. My two adult daughters make me happy, and a soon to be born granddaughter will not doubt add to that happiness.
Basically, I am a happy person who has had an amazing life that has been nearly always fun and happy. Sure, it has had is down moments, like losing my parents, but that is expected in life.
One of my happiest moments though, was when I just accept myself that I like to dress en femme. I went through the usual self doubt and internal battle, but when I finally just excepted the fact I enjoy dressing, that it hurts no one and that if anybody has a problem with me in a dress, it is their problem not mine. That realization was so liberating that it became a very happy turning point in my life.