It's not just about the l33t factor. Fans keep it cool when you have one or more powerful processors and/or graphics cards. My computer sounds like a B-17 getting ready for takeoff, but I've got a very powerful gaming box and NEED that cooling. My next box will be even hotter (power wise), but quieter because fans bearings and blade design have improved, the processors and graphics cards use less power meaning they generate less heat.
Look at a Retina iMac i7, or the Mac Pro, big power doesn't need to sound like a 747.