The best program I've found to do massive tagging is perl. I looked everywhere and couldn't find any program that worked the way I wanted it to, so I spent about an hour or so and wrote a perl script that pummeled through my entire mp3 collection (about 1300) and wrote ID3 tags based on the filename/directory.

if you are wondering why I didn't tag when I ripped, it's because I used to be anti-id3 (still am to a point). I prefer to store all information in the filename. I know it has its drawbacks, but I the advantages outweigh them imho. I like to use c:\mp3\Artist\Album\Track - Title.mp3 for normal music and c:\mp3\Album\Track - Artist - Title.mp3 for compilations. (my perl script handles both)