Before you go removing your cat, look into laws where you live. You dont wanna end up screwing yourself in the long run

 

Cat converters are a federal thing, so whether or not a lot of people have removed them doesn't alter legality. As previously mentioned, a lot of shops won't touch your car if the cat has been removed. Some States & Counties are more flexible, but 'technically' if your car came from the factory with a cat converter then to remain 'legal' the cat needs to stay.

Everyone has a different opinion on what sounds good, so you'll probably get numerous answers to your question. I'm running a Magnaflow dowpipe/cat and one of their 30" glasspacks in place of the resonator into stock mufflers. I like the way it sounds, but others may not. It's slightly louder at idle with a lower tone, sounds mellow on acceleration and doesn't drone at cruising or highway speeds. The combo of my exhaust and CAI has been complimented many times by some of the locals.