As the knowledgeable folks above have stated, you have to first define exactly what your preferences are, and what you budget is for the project. There are simply too many alternative and options available, and it is difficult for us to make recommendations, without some additional information from you.
I can tell you that for my 07 with the 6.2, I chose the Gibson Extreme cat back dual exhaust. First, I wanted a dual exhaust with two separate pipes in two separate outlet locations (just my personal preference), and I wanted a loud exhaust and tone to remind me of the late 60's muscle car sounds (again, just my personal preference). I really like the exhaust, but I fully acknowledge that most rational folks would consider it to be too loud.