I will attempt to answer this question seriously, however hard that will be.
Dash Berlin is crap, was crap, and will always be crap. He doesnt even produce unicorn trance. He produces fairy dust cupcake kate hudson starring llama trance.
Armin is crap and will be crap but at one time did have some great mixes, 2002 essential mix, and some really banging productions, Blue Fear a song even sasha used to close sets with. So no contest. Oh and also I did see him in 2001 when he was not famous yet and was super friendly and I had a blast so I cant hate him too much.