It's called the living room for a reason.
The living room is where the fun happens. All you need is your TV and a couch or recliner, and you're set for hours.
Kick up your feet and play video games, call your friends or watch movies. What you do in your living room is limited only by what you can fit in it, and since it's probably the largest room in your house, that should be anything you want.
You don't live with your mom anymore (not that there's anything wrong with that), so remember that your living room can also function as a dining room!