Having been away for the weekend I haven't had a chance to check these out yet but a publication sent to libraries etc. called Tips and Advice: Internet published by Indicator tested lyrics sites and gave these as its top three:
3rd http://www.lyricsplanet.com
2nd http://www.letssingit.com
and top with 250,000 lyrics , 16,000 albums and 12,000 artists was:
http://findlyrics.com

It has to be said they used pop songs as their test data.

RtS