Let me start by saying that there's no one specific best weight loss workout. You can find a large number of variations which can help you get excellent results. However, all the effective weight loss workouts have common characteristics which they all share. In this article, I'll relate for you the guidelines that you need to follow in order to make the most of each exercise session.
An effective workout for weight loss doesn't have to be long. In fact, if you spend more than an hour at the gym, you may even be hurting the process rather than helping it along. Don't make the gym your home. However, make sure that every minute you spend there is pure work time. It's not a place to socialize but to get lean.
The best workout for fat loss will consist of 2 segments: full body weight training and cardio training.
Weight training is something which many people overlook and it's wildly important for your results. The reason is that muscle mass burns a lot of calories just by being there. This means that the more lean muscle tissue you have the faster you burn calories even when you're resting. If you're looking to maximize your after workout weight loss, than you need to spend at least 20 minutes doing weight and strength exercises for all your muscle groups.
It won't matter which muscles you exercise because you can't spot reduce fat. However, working all of your body will help keep it in a balanced and healthy state and help to increase overall muscle tissue.
As for your cardio workout, you can make them pretty short as long as they're intensive. The way to do that is through high intensity interval workouts. These are highly effective workouts to lose weight and they're done by changing the pace and intensity of your workout every few minutes. For instance, you can run fast for 2 minutes and follow that by 2 minutes of walking. Repeat this cycle over and over again and you'll have a massive workout. You will also sweat like crazy but that's part of the fun, right?
If you make sure your workout sessions are a combination of these 2 parts, you will burn a lot of fat and do it faster than you could have otherwise.