I didn't see one of these for non-Si's so I figured I would start it up to help everyone out! Feel free to suggest anything because I know I missed some stuff. I will try to keep up with it.
Tsudo N1 Catback
Borla Stainless Steel Section
With my older Civic, i found Spoon Sports and T1R to be my top favorites for performance. I used some Injen parts in the past, but i ended up selling them within weeks of buying it.
What are your favorite aftermarket performance brands?