I think and believe, for the time being the best and most profitable way is buying and hold bitcoin. Based on my experience for almost 1 year, I've been able to profit more than 3 times or 300% just by buying and hold bitcoin until now.
Buying and holding the bitcoin is a good strategy. If you bought some bitcoin in early 2013, you might be rich.
Well we are not in 2013 we are now 2016 and nearly 2017.. but we can be still have a chance to be rich in bitcoin and i think it is still not late to hold a large amount of bitcoin and sell them in the right time to become rich someday.