I LOVE Xmas Eve. All the kids, even the grown up ones and Son IL come and watch Muppets Xmas Carol, a tradition since it was made when DC1 was small. We have a drink and eat an easy supper of open rolls and all those Xmassy snacks and cheesy nips.
Its fun and light hearted and nice.
I would cheerfully skip the day itself now the kids are all older, or rather I wouldskip the bit between presents (8am sharp) and everyone relaxing enough to be silly (usually about 4pm) as its just too much like hard work, even if someone else is hosting. The PRESSURE!!!!
My perfect day would be get up, Xmas Pant Head then mooch about, do presents about 4 ish and then a whole trifle to myself for my tea...... as long as my mother made the trifle!