Nothing comes close to MediaMonkey's performance along with a couple of scripts.
Some of my favorites being -
* Delete all album arts from the TAG from multiple songs (get rid of the website logos
)
* On the fly renaming of misspelled tags
* Duplicate finder
* Embed tags from links to tags
* Correct the Case
* Remove Prefix / Suffix
* Change FileName according to the Tags (Manually)
Use the scripts, specially AlbumArt Tagger, from this page - Scripts...
You could refer to these two articles as well - Alpha Geek: Whip your MP3 library into shape, Part II - Album art
Alpha Geek: Whip your MP3 library into shape, Part III: Metadata
Some of my favorites being -
* Delete all album arts from the TAG from multiple songs (get rid of the website logos

* On the fly renaming of misspelled tags
* Duplicate finder
* Embed tags from links to tags
* Correct the Case
* Remove Prefix / Suffix
* Change FileName according to the Tags (Manually)
Use the scripts, specially AlbumArt Tagger, from this page - Scripts...
You could refer to these two articles as well - Alpha Geek: Whip your MP3 library into shape, Part II - Album art
Alpha Geek: Whip your MP3 library into shape, Part III: Metadata