I know it is a strange question up to 3 months after having our babies, but I was on Facebook and I saw a picture of my cousins daugther being wheeled out of the hospital with the baby.
I realized that was my favorite moment with both babies! I was alone (except with the person pushing me) and DS and now DD cradled in my arms. (I've always sent DH down with the carseat ahead of time because both babies were preterm and had to pass the carseat test)
Feeling the fresh air and knowing we were going home to our little family. Those moments I can actually smell and feel when I recall them whereas the birth and first day or so is just so fuzzy. With DS it was also the first time it sunk in that now I was someone's Mommy.