VeryGnawty
I don't like treadmills. I run outside if I run or I take long walks. I do simple calisthenics or I find a place to practice parkour. If there's no wind on my face then I don't consider it exercise.
The way to go is low impact / high intensity. Rebounding is much better than treadmill. Calisthenics/bodyweight strength training and jogging. Stick to the basics. Push-ups, pull-ups, squats, isometrics. Avoid public gyms at all cost. They are just a place where you pay to swim in other people's sweat.
Look for parkour self-training videos on the internet. These exercises are all free (cost you no $$$) and most of the equipment can be found at a public park. If you have access to a bench or a picnic table, you will never need any exercise "equipment" because these objects can be used to work out every muscle in the body in just about any way you want them worked out. A tree with low-hanging branches is also a good exercise tool. Just don't scratch up the tree when climbing it!