One of my favorite hobbies (besides reading of course) is doing jigsaw puzzles. I (sort of) collect them, and I think I'm up to around 40 now. And I'm sure my love of puzzles partly comes from this family tradition.
For many years growing up, our family would get a puzzle from Santa for Christmas. Usually a snow covered scene or a panoramic landscape, or an artist my mom loved. But even though the pictures were usually more "adult" than kid-friendly, my family would all gather round the kitchen table either that evening or a day or two later and work on the puzzle. We'd get the border all assembled and then each take a little piece of the picture to work on until a day or two later it was all completed. Some years we were good enough to get it done in one day, but if we had a particularly hard puzzle it would linger around a little longer.
Putting together the puzzle itself is fun, but it's more than that. It's the ability to come together as a family and do something we all enjoy. Sometimes we talk, and sometimes we are just silent and enjoy each other's company. My brother and I usually get into a competition of some sort, but I usually win. I'm the undisputed "puzzle queen" in our family. But it was nice to do it for Christmas, since we kids didn't have school, so occasionally we'd get to stay up a little bit past our normal bedtime in order to finish.
One year we went to my grandparents for New Year's and introduced the tradition to them. Grandma likes to put in her one piece and then move on to something else, like a "I contributed my bit, now I'm moving on" kind of thing. Grandpa doesn't really like puzzles that much, but it drives him CRAZY to leave one sitting on the table overnight unfinished. Usually we start them in the evening, so he will sometimes stay up for hours trying to finish the puzzle. Sometimes we come downstairs in the morning to find it's complete, but sometimes not. I remember one year he'd been up for like 4 hours and I came downstairs in the morning and went plunk, plunk, plunk and unknowingly sunk three pieces he had been looking for all night (after looking at the puzzle for about 5 minutes). After I did that he decided he better take a break before he threw the whole puzzle off the table. :)