question to ask about what looks cool is too open and wide...just go with what you think looks good. The cases with the "turbines" are catching on though, they do look cool huh?
I think more than anything, cooling efficiency is very similar for all cases but it's up to you to take advantage of it. For example, many cases are designed for 3-4 fans and come with only one fan, usually the rear. Some people don't add fans, which of course they should.
Also, the new thing that isn't on many new cases is a top exhaust. Some suggest merely cutting a blowhole while others say to cut one for a fan.