I prefer to be called Mommy by DS.
Someone at preschool has been referring to the parents at "Mom" and "Dad", because recently he's been coming home calling me Mom.
ETA - I've never really thought about this... DS1 historically *always* called me Mommy. He had a speech delay, so by the time he was starting to talk, I guess "Mommy" was what he decided I would be... and I was so thrilled he was talking, I just became Mommy.
DS2 on the other hand, is a much earlier talker... he's been calling me "Mama" and his favorite food "Mama milk" since he was about 8 months old... I wonder if I will morph into Mommy with him, or stay Mama?
I guess I like both, but I think "Mom" is something older kids say, so I'm not really ready for my boys to call me that yet.