So years ago I had a crapload of music and I thought "Why would I ever want this filed any way but in one central "Music" folder and "Why do I care what album this is on" and so on.
Along comes Xlobby, where I want both. Filing a couple thousand mp3s in a certain order is quite a job, not even taking into account the poorly tagged/named files. And tagging them is just... It's overwhelming. That's why I had a pile of mp3s with poor tags in one central music folder for years and years.
Just a short time ago my brother stumbled on something called MusicBrainz mp3 tagger. There were a couple different programs, but they were very similar and had mostly the same function; analyzing the mp3 itself and figuring out what song it really is. Lemme tell ya... Just last night I retagged and refiled about 2000 mp3s last night. It spit about 500 back out saying that they were unidentifiable. So out of 2500-ish mp3s I'm down to about 500 that I need to do by hand. There's also different programs that run on different search variables, different databases... I can run these 500 through another program and probably drop it down to 250 or so.. It's flippin awesome.
Just look up MusicBrainz and it should tell you all about it.
I know this sounds like an infomercial, but it's freakin awesome.