Jay said:
To my ears, the best audio I've heard is newly pressed vinyl produced from analog master tapes. The DVD-Audio recordings I've heard come a close second.

I can't hear a difference between AAC files I've encoded with iTunes and the original CD recording, but I do think DVD-Audio sounds significantly better than CD, and good vinyl sounds even better than DVD-Audio.

The only people who would argue with that, and there is and endless supply of them, are people who have never listened to newly pressed audiophile vinyl mastered from the original master tapes on the proper equipment. It doesn't take an insane setup, just the right $300.00 amplifier, $200.00 phono amp, $300.00 needle, decent turntable, and decent speakers. Once you've heard such a record on such a system, there is no doubt, it's just better. I can't tell the difference between any good digital formats, but I can certainly tell digital from analog. It's a world of difference. It's sad really that so many people who are music freaks don't even give the superior format a chance. Those that do are always hooked. No matter how good a sample gets, it can't be an analog.