For the absolute best ride quality in most street cars, this KYB nitrogen-filled gas shock absorber would be our #1 choice.  The softer ride characteristics will provide the smoothest driving experience.  Sold each.  We recommend replacing them in pairs.

This particular shock is for a LOWERED application.  If your car is lowered with drop spindles only, or with adjusters and drop spindles, use the STOCK shock.  If it is lowered more than 3" with adjusters only, use this shock to prevent the shock from bottoming out against the shock tower and damaging either itself or the car's suspension components.