HKS Hi Power Exhaust- nice low tone at idle, and at WOT has a deep "quality" sound to it. Bad part is that it touches my rear bumper causin it to melt, but other g2's that i've seen hasnt had the problem.
I have the Apexi n1 and i love the sound but it is a little loud. im thinking about getting an axle back with the same size piping. NOt sure. would like a ws2 or sp2 or something like that