I just gotta say it: There is no one best exercise for everybody. Period. Don't waste your time looking for the final exercise answer.
We are all the same in some ways, and in others we're very different. I have a friend who's a runner. That's all he likes to do. I have a friend who's a skier and biker.That's all he likes to do. I enjoy many kinds of excercise, but not yoga. (Yep, I knew it. Yoga can be dangerous. The NY Times had a great article about the injuries caused by yoga excesses.)
If you find one or more forms of exercise you like and gets you close to the results (healthy weight, feel happy, strength) you seek, you're as close to the final desitnation as you will ever get. It's the journey, there's no final destination.
Months ago, you might remember the video posted here in which Dr. Mercola discussed High Intensity Training, including how he pushed so hard he felt dizzy and nauseous to attain the maximum benefits. Well in his latest Dr. Mercola talks about how he had to back off. The exercise was so intense that he could only do it once a week. Dr. McGuff, with whom he talks on the video in this post, advocates very slow, high resistance exercise for very, very short periods of time. His priority is to gain strength and cardio fitness in the shortest period of time. (He also makes an innane comment that you never see animals jog. Has he ever watched films of caribou migrating for hundreds of miles?).
I respect the research and earnestness that people like this put into their work. Both are worthy of attention because they know the human body. But what they advocate is very one-dimensional. If an exercise is too painful or uncomfortable or repetitious, few of us will continue to do it on a regular basis. Notice in how much Dr. Mercola frets about what is the right exercise, the right intensity, the right duration.
Movement of any kind is good. Hard, easy. Fast, slow. Inside, outside. Resistance, cardio. We exercise for all kinds of reasons. To stay healthy. To feel good. To fill the time. To compete.
Today it's snowing. I went to my favorite trail for a run. It probably wasn't very efficient, as I trudged up, slipping and sliding. But I breathed hard and my legs got sore and tired. Better yet, the snow was beautiful collecting on the sage.