This question comes up frequently, "What's the current most popular case?" Based on my observations as manufacturer / retailer, I'd say these 3 atm
($139) Fractal Design Define R6, http://goo.gl/SaLbfW
($69) NZXT S340, http://goo.gl/Y552Uy
($39) Cooler Master Masterbox Lite, http://goo.gl/2FFg7C
Why isn't In Win there???? There is no question that they make exceptionally good cases. Based upon my personal experience of working with In Win, I believe they don't focus enough of Marketing efforts at the US market. The majority of US based consumers IMHO are largely unaware of their brand. It's a shame, but those brands who engage with consumer, ultimately win sales.
and Yes, Corsair and Phanteks have contenders as well.