Borla, Bassani, and MagnaFlow are going to be the best quality systems out there.
MAC is cheap and sounds nice, but again its aluminized. Or they may be HTS coated like their headers. If you want an idea of what that will look like in a few years check out my shitty MAC headers.
I bought a Bassani cat-back 3 years ago and I love it. The quality is top notch and it looks just as good as the day I put it on. But you pay for that.