Among the application for creating backup copies of the CD or DVD as disc images (ISO images), Alcohol 120% is by far a great choice.
CDex is a great choice for any user that desire to extract audio CD on his hard disk in MP3 format having, in the same time, the advantage of being free.
CloneCD is a powerful CD copy software that creates copies of original CD's.
CloneDVD is a software that extracts, converts the code and burn an original DVD title on a single recordable DVD.
DVD Shrink makes backup of DVD discs offering edit option for modifying files as desired.
Game Jackal Pro saves the games CD's lives by creating disk image that allows to play games without requiring to insert the CD into the computer.
Data recovery from a damaged or poorly written optic supports is possible and easy to make with IsoBuster which also allow to browse the contents of an image file.
MagicISO is a program for creating / editing / extracting ISO images supporting a large number of images in ISO format.
RatDVD allows to fit into a single file, the entire contents of a DVD, like DivX / Xvid, but it preserves the variety of DVD content.
ShrinkTo5 is an appreciated tool that can copy movies keeping a superior picture quality.