So what encoder is the best? It depends largely in part as to what you are looking for. Some encoders are optimized for speed like the Xing MP3 encoder, others for quality, and still others for optimal quality at a certain bitrate. Below we have included links to sites that have taken the enormous amount of time to compare the various encoders and make some sense out of the madness. You can follow the link to their sites for a full explanation or just read their encapsulated conclusions.
Arstechnica - Nice rundown of Blade, Fraunhofer, LAME, and Xing.
The bottom line: Fraunhofer wins out at 128kbps, Fraunhofer and LAME the better at 192 with Xing improving alot at 256kbps (very close to CD quality). Read more at the site.
Discussion of Audio Compression - Detailed tests on the encoders.
The bottom line: Not recommended: Older Fraunhofer encoders like those found in MusicMatch 5.0, Nero 5.10, and CoolEdit due to problems with higher frequencies that few people can hear; MusicMatch 6.0 not recommended due to bug in latest Fraunhofer Codec; Xing encoding at 128kbps (higher bitrate produces better MP3s). Recommended at 128kbps are FastEnc and LAME v.3.88. MusicMatch 6.10 and above. Read more at the site.
MP3 vs CD Audio Quality Tests - Tests done using Fraunhofer's former BladeEnc program and using frequency analysis. Author concludes that 192kbps is very near CD quality. 2006 update suggested using the LAME Mp3 encoder and variable bit rate encoding.
Codec Listening Tests - Double blind tests using a variety of audio codecs including MP3, AAC, Musepack, WMA, Ogg Vorbis, and mp3PRO. Results varied across the board as to which was the best codec.
Do Higher MP3 Bitrates Pay Off? - Very interesting test to see if listeners could tell the difference in audio quality between tracks encoded at various bit rates. Results of the test recommend using Variable Bit Rate encoding.
We'll add more info and sites that do encoder reviews in the future. So what do we make of all these differing results? I think it just comes down to a person's ears. So, go ahead and download a few different MP3 encoding programs and give it a shot yourself. All you have to lose is time.