What makes our Pesach Seder special, and has for the past several years, is the wild rumpus that ensues when we visit my wife's family.
My wife has a small family, and she and her siblings grew up surrounded almost exclusively by one side of the family, with most of their cousins on that side living nearby, and all within a few years of each other. They would also spend most Friday nights and holidays - including Sedarim - together. They would congregate at Grandma's house, and they would run around and play games - and finish off the night watching their favorite TV shows.
As they all grew up, they started to move away from each other, both geographically and religiously. My wife started becoming more religious, and her cousins moved to different cities. At the time that we met, my wife had become fully observant, and when we got married we settled on the east coast.
Around that time, coincidentally, my wife's cousins had started to become more and more observant, and they eventually moved to Toronto. Suddenly, for the first time in several years, not only was it Halachically possible, but it was finally also geographically possible, for my wife to do what she had missed doing for so long: she could spend Pesach with her family. So, we did.
I grew up with different experience. My family is blessed with a lot of cousins, on both sides, and lots of aunts and uncles and great-aunts and great-uncles. My cousins - whom I love - are almost all much older than I am. A lot of them were going off to college by the time I was getting out of diapers, and the great-aunts and great-uncles were beginning to plan their moves to warmer climates for retirement. We had some memorable Pesach Sedarim, but by and large, by the time I hit my mid-teens, Pesach at my parents' house included me, my parents, my sister, and Bubby. From time to time we had other guests as well, including some regulars, but by no means was it as lively as I remembered it being as a small child.
Our first Pesach in Toronto was a brand new, eye-opening experience for me. There's no real way to describe the overall experience, so I'll just share one anecdote. At one point, the shenanigans got so out of hand that my wife's aunt ordered: "Children! Don't break the glass!"
You see, in their house they have a number of glass display cases. These cases are distributed throughout the house. My wife and her cousins were literally running through the house and tackling each other. And notice that her aunt told them not to break the glass. She did not say, "Hey, you're all in your 20s, start acting that way!" No, she said, "Children! Don't break the glass!" This behavior, to her, was normal, and they merely needed to be reminded to exercise caution in the vicinity of the display cases, but could otherwise be allowed - as adults - to run amok.
This is what makes our Pesach Seder special. It was so special, in fact, that the next year pretty much everyone who could - including Grandma, more cousins, and MY parents - joined in the party.
P.S. - The display cases have since been moved to more secure corner positions, located behind the head of the dining room table where it is not possible to run anyway.