Go to amusement parks! Except for the Ferris Wheel and the cable cars, it's good to go.
Play softball...I played some in high school and in the neighborhood, but have really let that go recently...whoops
Go to the beach, play frisbee, rollerskate, and all sorts of other summery things
Play in the snow: Sledding, snowball fights, making igloos, ice-skating, skiing (I want to learn to snowboard)
Photography...one of the only ways I can express my artistic talents. Can't draw, can't paint, can't write poetry...
Haha...I collect postcards. I have over 200 or so now.
Go on road trips
Sleep in
Read. You should really check out the following:

The Anne of Green Gables series by L.M. Montgomery (Still wonderful. I re-read them almost every year)
Atlas Shrugged and The Fountainhead by Ayn Rand (I don't totally agree with her philosophy, but the books are very well written and will captivate you for all 1,000+ pages!)
The Ender's Game series by Orson Scott Card
The Harry Potter series by J.K. Rowling
King Lear, The Tempest, and Twelfth Night by Shakespeare
The Lord of the Rings trilogy by J.R.R Tolkien
Possessing the Secret of Joy by Alice Walker
Song of Solomon by Toni Morrison
The Ten Big Farms by Dahlov Ipcar (My absolute all-time #1 favorite book when I was a kid!!!!!!!!)