Act out a play with costumes and makeup
Ask a grandparent about their wedding day or some of their most favorite fun moments. See more Fun Questions to get to Know Someone
Ask each member what their goal in life is
Attack a household chore as a team then go out and celebrate as a team
Build a fort with pillows from the couch
Buy a telescope and search out the stars and intergalactic life forms
Collecting all bad news from newspapers and making a ritual campfire to burn them
Go for a walk on a hiking trail or bike ride together in a national park
Go help a charity for the day
Get your bathing suit and go to a water slide
Go to the playground
Play a prank
Hang a bird feeder or go feed some ducks
Have a bonfire and roast marshmallows or make smores
Have a lemonade sale
Have a puzzle night - crossword puzzles, jigsaw puzzles or even a Sudoku Puzzle
Live in a cabin - with no power or water
Have a Backyard Vacation
Make up a funky dance with your children
Make up some instruments with spoons, ice cream pails and start a band
Make up superhero costumes and characters for everyone
Play Twister
Research your family tree
Take you lawn chairs blankets and junk food to the all night drive in
Try to get as many family members together in one place
Put on your bikini or swimsuit and have a Water Balloon fight
Take $5 each and go to a garage sale or a thrift store and see who can get the coolest purchases
Go play mini golf
Make a list of Fun Roadtrip Games and go on a Road Trip
Make a family fun video or stills with your camera phone or digital camera and post it on Youtube or Facebook
Have your own version of American idol
Get an astrology book and read the horoscope for everyones zodiac sign
Plan a party - make some crazy party invitations and party appetizers - Party ideas here
Go to a different park in your area every time you have a picnic
Set up some bird houses or bird feeders
Invite the neighbors over for high tea
Have a cooking party - or baking (some food ideas here)
Go through some old photo books or make some new photo books
Set up an emergency plan - invite your neighbors and see if someone from the fire department will come out and speak to the group
Use a GPS to go geocaching or adventuring in the woods
Get some old magazines, glue and put together a collage of your dreams
Make vacation plans for somewhere outrageous then work as a family to cut down expenses and save money so you can actually go
Make a family activity calendar
Get your digital camera or camera phones and go for a Photo safari. You all pick one theme and everybody has a contest to get a picture of that theme
Make some ice cream at home or just go to the ice cream parlor
Play charades or board games at the park or in the backyard
Get your bathing suit or bikini or whatever kind of swimwear and go to the beach
Go visit some other family members or friends
Go to a museum
Go to the zoo (other places to go here)
Go inline skating/ or ice skating more Adventure ideas and more Winter ideas
Play Basketball, baseball or touch football
Go for a whole week without internet, TV or video games
Play Frisbee, catch or kick a soccer ball around
Do something in nature, while you are there - identify bugs, birds, plants or animals
Go see a play or other cultural activity
Watch the sunrise or sunset together
Every month pick one member of the family who gets to be pampered all day long then pamper them
Go to a sporting event - professional or amateur
Have a slumber party (More Party ideas here). Plan out some cool party appetizers and then send home made party invitations
Listen to classical music while laying on the floor in the dark and talk about the experience..
Go to a farm
Have a Nintendo Wii or Xbox Live competition
Set up an Olympic Games obstacle course in the backyard
Create a Family "workout routine"
Start planing your Halloween Costume for next Halloween
Kidstuff/Children - Play Fun Fun Fun Games
Be the first to jump in the freezing cold swimming pool
Make a friendship bracelet
Blow bubbles on a child's belly
Make some sculptures with Play Doh
Buy some comic books 
Chase the ice cream truck
Design and build a time machine with friends. The wackier the better. Then bury it somehwere
Do some crayon art, finger painting or some other kind of Family Fun Craft
Do some hula-hooping
Draw with chalk on the road
Experiment with makeup
Get a Slinky and play with it
Get some chalk and play hop-scotch
Get yourself the coolest lunch box money can buy
Give balloons to people
Go buy a whack of firecrackers - Remember Safety First
Go fly a kite
Go to the park and play with the kids
Play freeze dance
Have a party
Have a water fight with the garden hose
Iddy Biddy Indy (buy some remote-control cars, set up a track, call your friends and have your own darn Indy Race)
Learn some magic tricks
Look for shapes in the clouds
Make a bridge across a stream or river. Be creative.
Make a tent over your bed with sheets and pegs and whenever you feel cold go inside and get cozy.
Partake in some yo-yoing
Play Barbie's
Play cops and robbers
Play hide-and-go-seek
Play kick the can
Play Tag
Play with some children's toys
Put a bell on your bicycle
Put on some big rubber boots and go puddle-jumping
Racing mini motorized boats or planes
Read a children's story
Ride a Pogo stick
Ride a tricycle as if you were 4 years old again
Ride the kiddy rides, especially the ones in the mall
Roll down a hill
Run a model train
Set up a treasure hunt
Spin until you're dizzy
Stand on your head
Take off your shoes and splash your feet in a fountain
Wade for minnows
Wear your hair in pigtails.
Write down wishes in a book and call it "my wish list" check periodically to see how many come true.
