My family and I are thinking of getting another dog. We already have a jack russle who seems to be aggressive at first but quickly calms down to the dog. We have already had a Beagle (that we sadly had to give away because she ran away all the time) and a Aus. CAttle Dog Cross (who was perfect for us but needed more room to run.) We had a medium sized back yard with a low fence, so I wanted a large-meduim dog, but it seems they are all able to jump over our 4 1/2 ft. fence. Also I'm not able to provide walks ALL THE TIME like Aus. Cattle Dog would need. We wanted a big dog: that had enough sense to stay in our yard,(even if it got bored it cant just wander off) be trained easily, was able to be off leash, and wasn't always bouncing off the walls. We have a lot of restrictions to our dog, sadly So I would just like to hear everyone's opinions on what they think the right breed would be.

I'm sorry to say that with all your restrictions it doesn't sound like you should get a large dog. Just letting the dog out in the yard wouldn't be enough exercise for a big dog...and maybe not for most dogs. I don't know how often you mean by walking "all the time" but if you got a medium to large sized dog and were able to take it for a long walk/jog once a day, it would probably be fine. All your other requirements follow from the dog getting enough exercise. A dog that is well exercised will be easy to train, will be more likely to stay in the yard, and won't be bouncing off the walls. A dog that is easy to train can be taught to come back when you call so it can be off leash.

Sorry for not giving more specific dog breeds, but as I said, the restrictions you gave have a lot more to do with how much exercise the dog gets than the breed. Obviously if you've thought of a breed you like you'll want to do some research and make sure it's a good match and not exceptionally high energy. For breed information, especially temperament, I like this website:
http://www.dogbreedinfo.com/

Also, you'll need to consider the individual dog. My parents have a lab that is very high energy for her breed. They take her to a park every morning to let her play with other dogs and run full speed. If they didn't do this, she would have been untrainable and a terror in the house. Since they do, she made it through guide dog pre-training as a star student (she was released from the program for medical reasons) and now is the best behaved pet anyone could ask for.