I'm positive that many things will come and go as "my favorite thing about being a dad". Here is my current #1.
So far over the course of Erika's pregnancy I (being a responsible parent-to-be) have been reading different websites trying in vain to "know it all" before Otto's street date. One of the things I read talked about playing games with him while he's still in the womb. So most nights when we would go to bed in the evening I would try tapping on Erika's belly trying to get him to respond by kicking where I would tap. So naturally since he's our son, he decided to be stubborn and I never got a kick in return and Erika would just end up getting beat up on the outside of her tummy as well as Otto abusing her from the inside.
A couple of nights ago we we're watching some TV after a long day at work and I was mindlessly touching her belly and felt him move around so I leaned over and gave a loud kiss right on the area where he was moving and he responded, made another loud kiss, he responded again we did this back and forth for a few minutes and it was seriously one of the happiest most fun times of my life. It kind of made it feel more real that our child was in there and soon going to make his grand arrival in our lives and to the outside world.
I don't want to rush my son to grow up I want us to enjoy him in every age and every stage of development, but I can not wait until he's old enough for he and I to play more silly games. And overtime as he learns a new one, I'm sure that one will be my new #1.