One of my favorite strategy ( and most successful for me) is Trend following. It is simple and easy to implement , however not everyone can follow it due to lack of discipline and double digits drawdown.
GLD is currently trading above it's 10 month moving average. If it closes above it's MA this week, I will go in Monday morning. To give you an idea how this strategy performed in the past ( since 2006), please see below :
Buy Sell P&L % Months in Trade
Nov 30, 2006 Aug 29, 2008 +26.90% 21 Dec 31, 2008 Dec 30, 2011 +75.67% 36 Jan 31, 2012 Mar 30, 2012 -4.25% 2 Aug 31, 2012 Jan 31, 2013 -1.84% 5
As you can see the holding time is pretty long , however , the returns are fantastic !