What is the best way to clean dvds and cds?

You can buy a kit, or just use rubbing alcohol and a soft, lint-free cloth, and rub gently.

What is the best way to clean dvds and cds?
For scratched CD's or DVD's, toothpaste works great. I know it sounds strange, but the mild abrasives will remove surface scratches. Use a little toothpaste and a small amount of water and gently scrub the surface with a cloth. Be sure not to use a circular motion (around the disc), always wipe across the disc from the center to the edge. A circular motion used in any kind of cleaning can create small scratches that throw off the laser tracking.
I've only had to use this method twice, but it worked like a charm both times.