If u wanna keep your whole exhaust system stock, and just change out the muffler, then definately go for a Flowmaster muffler, the 40 series are the loudest, but i kinda like the 40 series Delta Flow muffler, It sounds almost identical to the Original 40 series, but theres less in cab noise. Which is a godsend for daily drivers who go on the highway daily. But if u wanted to go all out and get the best performance, and best sounding exhaust system, go with a 2.5 inch diameter pipe coming out from behind the catalytic converter, run it into a (Single 2.5 inch Inlet / Dual 2.25 inch Outlets) Flowmaster 40 series Delta Flow muffler, and then run 2.25 inch diameter mandrel bent pipes all the way out to the back. If u wanted to, throw on sum 3 inch chrome tips for looks.