There are many types of credit cards where you can earn points for free air or train travel, free hotel nights, etc. I currently use an Amtrak Guest Rewards credit card. I only have to earn 3000 points to get one free ticket on the Boston to Washington route. I use my card almost everyday and I purposely do this to accumulate points.
For years, a family member of mine has been using a Marriott credit card and has been earning free hotel nights. You have to earn about 30,000 points though to get one free night, which is a lot and can take time to earn depending on how much you use your card.
This free night at a Marriott Hotel does not need to be used far away from home. It can even be around the corner from where you live. Whether you live by yourself, with a spouse, or a family and children, this is a great opportunity to get away for even one night. Look at it as an inexpensive mini vacation even if it is for only one night. If you go by yourself, you can just enjoy your hotel room or other amenities that the hotel offers. Most hotels have swimming pools, spas, game rooms, etc.
No matter how far away from home, the kids will just love the idea of going to the pool, using the arcade and staying up late to watch the Cartoon Network. There will be some cost involved for food and the arcade room, but keep in mind that when you go on vacation, the hotel is probably the most expensive thing that you will pay for. It would also be fun for the entire family to eat out in the hotel restaurant for dinner. Many hotels serve a free continental breakfast too. If you do not want to eat at the restaurant, which can be costly, the kids would love to go to any place in the area to eat, like McDonalds. Then, they can use the play area afterwards.
Doing something like this can be a very inexpensive, but still fun weekend getaway for the family. If I did not need the points to travel Amtrak, I would definitely get a Marriot Credit Card and start accumulating points.