The festivities usually start a little early for me, personally, due to the fact that my birthday is a few days before Christmas. My birthday's not usually anything too big, just some cake and ice cream and my presents (which might as well be early Christmas presents, honestly). I should see if I can get anybody over my house for a bit.
On the 23rd, we go over to Nana and Papa's house (the grandparents on my mom's side). It's a pretty big get-together with lots of food and family from my mom's side. It's sort of a Christmas party and sort of Channukah because Papa's Jewish (I am not), so there are potato pancakes among the many other snacks and entrees. Around 6 o'clock or so, we then deal out presents. The different families have gifts in color-coded tissue paper (my branch is usually green). A lot of us also have gifts to pool for the Yankee Swap, usually themed on a color (this year will be yellow... for some reason. Why not just "gold"? That's Christmas-y). It's a pretty fun time, the food is plentiful, some of my cousins are alright, it's a fun time.
The 24th is a bit quieter, usually. Not much happens in the daytime, but I think my aunt and uncle a couple of towns over have a party. Only Mom and Dad used to go there, but I went last year. There aren't a lot of people to talk to, but one of my older cousins is pretty enthusiastic about old-school games, so there's a good conversation. There are a lot of deserts spread out, too, and I think I was drinking root beer from a mug from the freezer. ...that had some ice in it.
Christmas morning is the highlight (the Myotismon arc of the holidays, if you will :P). Presents are strewn about the tree, some wrapped, some unwrapped. It's just the immediate family at home (Mom, Dad, and my sisters). We exchange our own gifts to each other, and we're pretty ecstatic. Dad usually has the camcorder running as we open our presents, and there are a lot of them (takes like an hour to get through everything: wrapped, unwrapped, and stockings). Once that's over, we get cracking on breakfast, with pancakes, bacon, scrambled eggs, home fries, and cinnamon buns (this was actually my idea years ago). So much salt... so much syrup... so much deliciousness.
Of course, the day's not over yet. We kids take time to play with some of our toys, but around noon or 1, we head over to Vovo's house (grandmother on my dad's side, and the house is only about a half-mile away from ours), where a lot of the family meets and talks (or avoids each other). There's dinner, usually ham, and we exchange gifts to the youngest among us (in which I am no longer ranked). And the rest of us do ANOTHER Yankee Swap (because it succeeded the first time around at Nana's, we started doing it here, too). Then, we just kind of go our separate ways. This part's not quite as big, probably because we were just over there for Thanksgiving, but it probably has the most people I can actually hold a conversation with, so that's gotta be worth something.
So... tl;dr: My family is huge, and I am spoiled rotten this time of year usually. ;)