1.Watch TV and Movies
You don't have to have cable any more if you don't want to. Many popular TV shows and movies can be watched through services like Netflix or Hulu, which can even stream right to your TV. These usually cost money, but it's much, much cheaper than paying for cable.
2.Watch YouTube
Youtube carries all sorts of different video content. You can watch funny clips, family movies, full TV shows, full movies, clips of either of those things, or even just do things like listen to songs.
3.Play games
You can play games online (or even gamble!). Websites like Games.com offer lots of free, classic games that you can play. Another option are games like fantasy football: a number of league are available online that you can enjoy for free.
4.Listen to music.
You can also listen to music online. There are many free websites that let you listen to music that you like. Pandora is a free internet radio that lets you choose what kind of music to listen to. Slacker.com is similar to a satellite radio service with a wide variety of music of all genres. You can also try to bring up specific songs or artists using websites like YouTube.