Whats the best workout to lose weight?

Slow exercise best. Research shows that fast exercise (breathing hard) burns carbs and may trigger carb hunger. Slow exercise in which you can still carry on a conversation keeps the exercise aerobic and burns fat. Doesn't trigger post-exercise craving. Just build this into daily regimen by parking at far end of parking lot, climbing two flights of stairs every day, and eating proteins and veggies.
High intensity. If you're not currently active, any increase in activity will help. If you have some health problems, visit your doctor before starting an exercise program. After you build up a base of activity with slower activity and weight training, there is an indication that high intensity exercise may be best for weight loss. Exercise for 30 min with a heart rate of around 80% max. Intervals are good.