Mp3 tagging software.....what's best ?

I have a fairly hefty collection of music on an external hard drive. Some of it has all the correct track definiitions i.e. track, artist, album, genre etc but alot of it doesn't.
I've used a trial of "Tag & Rename" which isn't bad but before I buy a license I want to see if anyone can recommend anything better for the job ?

Cheers

dont pay. itunes, media monkey, godfather. Loads of tagging software out there.
Iv used them all and more, Godfather is supposed to be the best but if you have a load of music, it can only tag based on the name of the file and make a guess which it will prompt you to confirm so Ive seen no real difference.

Be prepared to spend a lot of time tagging and UNtagging when you find out it guessed the wrong name of the album and artist and you clicked ok.

google for links or go to the audio section of 100-downloads.com

busicbrainz and "tag & rename" are a combination thats hard to beat

Media Monkey is my fav. Probably a combination of a couple is best. Depends if you've mainstream music or not.