There are many good options and I'm sure others will weigh in with their advice. If you want a quieter pipe and are not concerned as much with performance, the Triumph Off Road pipes are nice quality pieces and are not excessively loud. If you want a little more sound and better airflow, S&S, Bubs, D&D's are some of the names I have seen. Also, you can have you stock pipe gutted for relatively cheap dollars - take a look at the classifieds section.
