Well its all personal pref. IMO. I have a Magnaflow muffler and now that its broke in, man does it sound good. Nice low tone and definatly doesn't sound like a V6. The Flowmaster's sound great also, but they suck performance wise.
If you want great sound, and performance, go with Borla. But, you get what you pay for...hence the reason why Borla is soooo expensive. Not like Magnaflow is either...my stainless steel Magnaflow 2.5" SI/2.5" DO muffler was $100. Check out the sound clip of my exhaust in my sig if you want to know what it sounds like.
2003 Ford F-350 Super Duty
: 6.0L TurboDiesel V8, 4x4, Auto. All stock...for now
1989 Ford Mustang GT
: The fun machine.
-AOD rebuilt w/thicker clutches
-B&M Shift Kit
-BBK Chrome Shorty Headers
-BBK 65mm Throttlebody
-Ford Racing 65mm EGR Spacer
-MAC Cold Air Fenderwell Intake
-Summit racing double roller hydraulic timing chain
-Summit racing underdrive pulleys
-Ford Racing A/C delete
-Custom true dual 2.5" Magnaflow exhaust