The Zune software was the best, if you can still install it. It's sort of like MusicBrainz Picard but with a professional interface, and will tag a totally untagged album based upon file lengths, which little else will do.
mp3tag.
I feel a tinge of sympathy for the people who think they have tagged everything in iTunes, which for reasons of Apple insanity tends to only update a local register not the actual files.