What I've read about pipsminer tends to echo Rsmereka's opinion. I'm not sure that's the EA for me.
I do not use robominer (little pricey for me right now,) but I know it's very well proven....I've seen nothing but good things.
I'm researching megadroid right now and that will be the first one I test.
My next endeavor will likely be Equity Builder over euro blaster....it sounds interesting.
And Megadroid works well, but it needs to be set up properly and used with the proper
broker 
. Also, I've heard Advanced Droid Tactics settings for megadroid are amazing. Unfortunately, they are down for business at the moment.