Everyone knows lossless is better than lossy. But there's subtle differences between lossless formats themselves! So, here are the 5 contenders for the title of best lossless format: ALAC (Apple Lossless) AIFF FLAC WavPack WAV Here, ALAC, FLAC and WavPack are compressed while WAV and AIFF are uncompressed. Some people argue that the extra decoding required to extract audio from the compressed files will affect sound quality (which I hope not). Also, only ALAC, AIFF and WAV are supported by iTunes. I know some people will say "Lossless is lossless; there isn't a difference between whatever codecs they use" but I just want to hear which format you prefer.