A community of 30,000 US Transcriptionist serving Medical Transcription Industry
but I'd like to hear any other suggestions also since I'm in a trial period of one now myself.
This one has great clarity and volume and is free (mainly for court reporter use, though works fine for MT files). I had some issues with it that were partly related to my system, but worth a try and would still be my first choice for quality of sound:
http://www.fortherecord.com/products/player
http://community.fortherecord.com/index.php?/files/file/1162-therecord-player-562
Some instructions for use:
http://forum.mtstars.com/485588.html
http://forum.mtstars.com/481125.html
This is the one I'm using now, Transcription Buddy (free month trial, $39.95 to buy), still tweaking the options and settings. I really like it for its maintaining pitch well when slowing down or speeding up, which TheRecord Player does too, both much better than Express Scribe for that, in my opinion. This one doesn't have quite as much volume as TheRecord Player did for me, though.
http://www.libertyrecording.com/TB_main_Player.htm
Reviews of TB (I don't download from CNET anymore, just read the reviews there; all their downloads seem to get packaged with bloatware now). Check out the replies too.
http://download.cnet.com/Transcription-Buddy/3000-2064_4-10221579.html