I have been with the same question for long time,i try a lot of demos and i have been usin 4 months now one that i buy from
http://forexrobot.eu.com/forex-brilliance.html and its called Forex Brilliance,in 120 days i have invest a serious amount and i let it alone to see how it works,the results is amazing,for me is the best invest that i have make,so the better thing you have to do is try one and see how it goes for you,dont waste time!