Why can't I be the fun parent?

I often watch how excited my children get when they get to play with my husband.  He is the fun parent while I am the everyday parent.  They don't get to see him all that often as he works long hours and I am home full-time with them but it still hurts my feelings sometimes.  We go out to eat and they want to sit next to him, on the weekends all they want to do is play with daddy and I often feel like chopped liver.  He will rough house with them while they say they can't rough house with mommy because we have to be careful of mommy.  I try to tickle them and rough house with them but end up covered in bruises and they get tired of me saying, "Ouch, be careful".

During the week, I take them to fun places and we meet with friends usually about 3-4 days out of the 5 day week but they seem to need more from me and I just can't give it to them.  It breaks my heart but I'm not sure exactly how to give them what they need.  One of the meds that I take is for extra energy but it doesn't seem to help enough to keep up with a 4 & 5 year old.

I probably overcompensate by taking them all of these places and they have come to accept it but am I just "buying their love" because I can't play as often I like and they like.  They seem like well-adjusted children but I worry that they are missing something.  Are they going to look back on their childhood and just remember good times with daddy? I give it everything I have but it just doesn't seem like it is enough.