The best sounding exhaust on a gsr integra imo is the Tanabe hyper medallion. Not too loud or too quiet, it has a nice deep rumble through the entire rpm range. Sound just as great decelerating as it does accelerating and doesn't drone cruising. I got more compliments with the Tanabe hyper then both my Mugens. I had the twin loop and currently the sir-g single pass. The GReddy evo and Apexi w2 sound great too, but the Tananbe hyper has a very distinct clean sound that's hard to get with a 4cylinder engine. The drawbacks I saw with the Tanabe is the louvers in the resonator and weight of the muffler if you're looking for max power and weight saving. However, it's probably one of the nicest street exhaust system out there.