No kids or grand kids, but lots of nieces and nephews! We played our fair share of board games and puzzles, and lots and lots of Lego. We took them out on many fun adventures (the zoo, fishing, movies, amusement parks...). We got them full of fun and sugar and took them home for the parents to deal with!
One adventure our nephews still talk about is the day we piled them into the back of the car, took them to A&W, filled them full of root beer and taught them how to belch!