In theory, a CD should sound better than a record. It's a digital format that requires no physical contact with the player's pickup device to be read, so there's nothing to wear out. The every copy of a specific album will sound identical on the same system, regardless of the CD's age, room temperature or how often the player is used. Since it's a digital format, it's less affected by external influences and extranious noise is nearly absent (in fact, a CD sound is so clean, artificial noise is often added to avoid negative affects on people who use headphones to listen to them).

Records wear out the more you play them. Dust and scratches created pops and crackles during playback. Both the records and the equipment are affected by temperature. In addition, the materials that make up records as well as the type of circuitry in the stereo equiment tend to skew the sound.

Those that prefer records like the very properties that make them less than perfect. Those listeners assert that records have a more "organic" sound. Because our ears are analog and imperfect, it's believed they relate better to analog and imperfect sounds.

In the end, it's up to the individual listener to decide what the prefer. Just like different people have different preferences for what type of music they listen to, they often prefer different methods of listening to it.