Although people seem to laugh at the idea, i went with an 18" glass pack inline with my exhaust. I did have just a catalytic converter and a muffler before, and it was loud/buzzy and busting gaskets. I had to get a flex pipe (to stop breaking gaskets), and looked at resonators. I ended up with an 18"x2¼" glass pack (the poor-man's resonator), which was $20, and the labor was $20 to weld it into my existing exhaust. The flex pipe was $80 for parts+labor. Anyways, the glass pack took the racket out of my exhaust, and it's a LOT more pleasant to drive, especially around 3500-5000 rpm, where it was unbearably boomy and buzzy before. It added some much needed low-end torque, and the car accelerates better with the additional back-pressure. I realize I'm going to get flamed with people telling me that the glass pack will wear out and sound like ass, but eventually, I intend to get a cat-back exhaust with a resonator, when I can afford a good one.... and by then I might be going turbo anyhow.
I like that my car is back to sleeper with the glass pack, albeit temporary (glass packs deteriorate quickly, I'm told).
-x