It depends on if my husband is working on Christmas Day or not--he works 24 hour shifts, so if he is working, we can't just wait for him. If he is working, we have our Christmas at home on Christmas Eve day...when the kids were little, "Santa" always knew he would be working and came the night before.
Christmas morning we start at home (unless hubby is working). The kids open their stockings, and MIL/FIL come over around 8:30 or 9:00 to watch the kids open the gifts they got here, and we have breakfast at the same time or after, which is some kind of hashbrown/cheese/ham/sausage/egg casserole with fruit, cinnamon rolls, whatever else sounds good. The ILs leave and we get ready and go to DH's aunt's house, where there is brunch and gifts with the whole family (his parents, siblings, grandma, aunt, cousins and their kids, a couple of friends, anywhere from 18-25 people or so, depending on who comes from out of town). When we are finished there, we go all down the road to the ILs house for cookies, snack food, coffee, 24 hours of A Christmas Story, stockings for all the kids (big and little) and more gifts, kids playing with toys, and we are there until 3:00 or 4:00. The whole crew moves on to grandma's house up the road, where we sometimes lose a couple of people who have other places to go, and we pick up a couple of other friends who stop by. She has appetizers out when we get there, then we have Christmas dinner, football or movies on tv, and more gifts afterwards.