A common misconception about physical exercise is that the benefits gained are somehow separate from overall personal well-being. This is simply not the case.
On a person-to-person level, health benefit or gain can vary greatly. For example, a person who has never engaged in physical activity will have huge gains in health benefits and fitness level by going from working out 0 times per week to 2-3 times per week, regardless of the type of exercise they are engaging in. For a person who is already working out 2-3 times per week and increases their physical activity to 3-4 times per week, their level of improvement or health benefit will increase on a smaller scale. This is the reasoning behind "pushing the plateau" once you reach a very high level of fitness, because it is very difficult to see a huge health benefit or gain if you are already very physically fit. In this sense, "whatever the trainee wants" is very important in determining what types of exercises will have the greatest benefit.
If you're looking for a simple answer, I am sorry to say that you won't find one here. Let's think of it in Bruce Lee terms: "A fight is not won by one punch or kick." In the same way, health benefits are not maximized by one type of exercise or one type of well-being. To maximize your health benefits, you must incorporate other aspects of wellness into your life. Yoga is a good example of this. To maximize the health benefits of yoga, you have to train your mind as well as your body. If you only go through the physical movements of yoga, your flexibility will increase but you will miss out on the great inner peace that comes when you are able to train your mind as well. If you think of exercise as just a way to gain muscle or endurance, you haven't thought it through yet.
Finally, the best way to find out what physical movements and exercises are best for you is to find a local health coach or personal trainer that can help you make realistic and attainable health goals. Also, get a physical from your physician so you know what sorts of activity are safe for your body and your health.