In the tradition of Mad-Libs, here’s a great site that will give you hours and hours of family fun.
In this classic phrasal template word game, one player prompts others for a list of words to substitute for blanks in a story, before reading the often comical or nonsensical story aloud. There are over 2000 user-created children’s stories on Word Blanks, including favorite nursery rhymes, children’s stories, theme songs and original stories.
Most of these are perfectly fine for all ages, but a very few can get a little “kid gross”, so you may wish to preview the stories before playing them.
CLICK HERE to go to the site!
If you have a stash of LEGOs in your home, here’s a terrific little project that kids of all ages will be absolutely fascinated by, courtesy of 
TheHappyHousewife.com has a great collection of almost 100 hands-on projects, crafts and experiments especially for homeschoolers, on all sorts of interesting topics, including:
From the HowDoesShe? blog comes these way fun printables that do wonders to promote some fun family discussion around the table: 
Children’s book author Lou Treleaven has a unique crafts site that offers dozens of downloadable, printable “cootie catcher” paper toys of all sorts. It really stretches the boundaries of this traditional children’s paper toy.